update tutorial format

docs/about-connection-context.md

@@ -105,4 +105,4 @@ int some_function()
 }
 ~~~
 在这个示例中，当http task是连接上的首个请求是，我们设置了cookie。如果不是首个请求，根据约定，不再设置cookie。  
-另外，prepare函数里，可以安全的使用连接上下文。同一个连接上，prepare不会并发。  
+另外，prepare函数里，可以安全的使用连接上下文。同一个连接上，prepare不会并发。

docs/about-counter.md

@@ -203,4 +203,4 @@ public:
     ...
 };
 ~~~
-有需要的用户可以自行查阅相关代码。由于WFTaskFactory没有提供工厂函数，创造container任务需要自己调用new。  
+有需要的用户可以自行查阅相关代码。由于WFTaskFactory没有提供工厂函数，创造container任务需要自己调用new。

docs/about-error.md

@@ -29,14 +29,14 @@ void callback(WFXxxTask *task)
 ~~~cpp
 enum
 {
-	WFT_STATE_UNDEFINED = -1,
-	WFT_STATE_SUCCESS = CS_STATE_SUCCESS,
-	WFT_STATE_TOREPLY = CS_STATE_TOREPLY,		/* for server task only */
-	WFT_STATE_NOREPLY = CS_STATE_TOREPLY + 1,	/* for server task only */
-	WFT_STATE_SYS_ERROR = CS_STATE_ERROR,
-	WFT_STATE_SSL_ERROR = 65,
-	WFT_STATE_DNS_ERROR = 66,                   /* for client task only */
-	WFT_STATE_TASK_ERROR = 67
+    WFT_STATE_UNDEFINED = -1,
+    WFT_STATE_SUCCESS = CS_STATE_SUCCESS,
+    WFT_STATE_TOREPLY = CS_STATE_TOREPLY,        /* for server task only */
+    WFT_STATE_NOREPLY = CS_STATE_TOREPLY + 1,    /* for server task only */
+    WFT_STATE_SYS_ERROR = CS_STATE_ERROR,
+    WFT_STATE_SSL_ERROR = 65,
+    WFT_STATE_DNS_ERROR = 66,                   /* for client task only */
+    WFT_STATE_TASK_ERROR = 67
 };
 ~~~
 ##### 需要关注的几个状态：

docs/about-service-management.md

@@ -30,19 +30,18 @@ using upstream_route_t = std::function<unsigned int (const char *, const char *,
 class UpstreamManager
 {
 public:
-	static int upstream_create_consistent_hash(const std::string& name,
-											   upstream_route_t consitent_hash);
+    static int upstream_create_consistent_hash(const std::string& name,
+                                               upstream_route_t consitent_hash);
 
-	static int upstream_create_weighted_random(const std::string& name,
-	                                           bool try_another);
-
-	static int upstream_create_manual(const std::string& name,
-									  upstream_route_t select,
-									  bool try_another,
-									  upstream_route_t consitent_hash);
+    static int upstream_create_weighted_random(const std::string& name,
+                                               bool try_another);
 
+    static int upstream_create_manual(const std::string& name,
+                                      upstream_route_t select,
+                                      bool try_another,
+                                      upstream_route_t consitent_hash);
 
-	static int upstream_delete(const std::string& name);
+    static int upstream_delete(const std::string& name);
     ...
 };
 ~~~
@@ -137,7 +136,6 @@ int main()
     UpstreamManager::upstream_add_server("redis.name", "10.135.35.55");
     ...
     UpstreamManager::upstream_add_server("redis.name", "10.135.35.62");
-
 
     auto *task = WFTaskFactory::create_redis_task("redis://:[email protected]/2?a=hello#111", ...);
     ...
@@ -164,21 +162,21 @@ struct EndpointParams
 // In UpstreamMananger.h
 struct AddressParams
 {
-	struct EndpointParams endpoint_params; ///< Connection config
-	unsigned int dns_ttl_default;          ///< in seconds, DNS TTL when network request success
-	unsigned int dns_ttl_min;              ///< in seconds, DNS TTL when network request fail
+    struct EndpointParams endpoint_params; ///< Connection config
+    unsigned int dns_ttl_default;          ///< in seconds, DNS TTL when network request success
+    unsigned int dns_ttl_min;              ///< in seconds, DNS TTL when network request fail
 /**
  * - The max_fails directive sets the number of consecutive unsuccessful attempts to communicate with the server.
  * - After 30s following the server failure, upstream probe the server with some live client’s requests.
  * - If the probes have been successful, the server is marked as a live one.
  * - If max_fails is set to 1, it means server would out of upstream selection in 30 seconds when failed only once
  */
-	unsigned int max_fails;                ///< [1, INT32_MAX] max_fails = 0 means max_fails = 1
-	unsigned short weight;                 ///< [1, 65535] weight = 0 means weight = 1. only for master
-#define SERVER_TYPE_MASTER	0
-#define SERVER_TYPE_SLAVE	1
-	int server_type;                       ///< default is SERVER_TYPE_MASTER
-	int group_id;                          ///< -1 means no group. Slave without group will backup for any master
+    unsigned int max_fails;                ///< [1, INT32_MAX] max_fails = 0 means max_fails = 1
+    unsigned short weight;                 ///< [1, 65535] weight = 0 means weight = 1. only for master
+#define SERVER_TYPE_MASTER    0
+#define SERVER_TYPE_SLAVE     1
+    int server_type;                       ///< default is SERVER_TYPE_MASTER
+    int group_id;                          ///< -1 means no group. Slave without group will backup for any master
 };
 ~~~
 大多数参数的作用一眼了然。其中endpoint_params和dns相关参数，可以覆盖全局的配置。  

docs/about-timeout.md

@@ -13,18 +13,18 @@
 ~~~cpp
 struct EndpointParams
 {
-	size_t max_connections;
-	int connect_timeout;
-	int response_timeout;
-	int ssl_connect_timeout;
+    size_t max_connections;
+    int connect_timeout;
+    int response_timeout;
+    int ssl_connect_timeout;
 };
 
 static constexpr struct EndpointParams ENDPOINT_PARAMS_DEFAULT =
 {
-	.max_connections		= 200,
-	.connect_timeout		= 10 * 1000,
-	.response_timeout		= 10 * 1000,
-	.ssl_connect_timeout	= 10 * 1000,
+    .max_connections        = 200,
+    .connect_timeout        = 10 * 1000,
+    .response_timeout       = 10 * 1000,
+    .ssl_connect_timeout    = 10 * 1000,
 };
 ~~~
 其中，与超时相关的配置包括以下3项。
@@ -40,24 +40,24 @@ static constexpr struct EndpointParams ENDPOINT_PARAMS_DEFAULT =
 ~~~cpp
 struct WFGlobalSettings
 {
-	EndpointParams endpoint_params;
-	unsigned int dns_ttl_default;
-	unsigned int dns_ttl_min;
-	int dns_threads;
-	int poller_threads;
-	int handler_threads;
-	int compute_threads;
+    EndpointParams endpoint_params;
+    unsigned int dns_ttl_default;
+    unsigned int dns_ttl_min;
+    int dns_threads;
+    int poller_threads;
+    int handler_threads;
+    int compute_threads;
 };
 
 static constexpr struct WFGlobalSettings GLOBAL_SETTINGS_DEFAULT =
 {
-	.endpoint_params	=	ENDPOINT_PARAMS_DEFAULT,
-	.dns_ttl_default	=	12 * 3600,	/* in seconds */
-	.dns_ttl_min		=	180,		/* reacquire when communication error */
-	.dns_threads		=	8,
-	.poller_threads		=	2,
-	.handler_threads	=	20,
-	.compute_threads	=	-1
+    .endpoint_params    =    ENDPOINT_PARAMS_DEFAULT,
+    .dns_ttl_default    =    12 * 3600,    /* in seconds */
+    .dns_ttl_min        =    180,          /* reacquire when communication error */
+    .dns_threads        =    8,
+    .poller_threads     =    2,
+    .handler_threads    =    20,
+    .compute_threads    =    -1
 };
 //compute_threads<=0 means auto-set by system cpu number
 ~~~
@@ -97,10 +97,10 @@ class WFNetworkTask : public CommRequest
 {
 ...
 public:
-	/* All in milleseconds. timeout == -1 for unlimited. */
-	void set_send_timeout(int timeout) { this->send_timeo = timeout; }
-	void set_receive_timeout(int timeout) { this->receive_timeo = timeout; }
-	void set_keep_alive(int timeout) { this->keep_alive_timeo = timeout; }
+    /* All in milleseconds. timeout == -1 for unlimited. */
+    void set_send_timeout(int timeout) { this->send_timeo = timeout; }
+    void set_receive_timeout(int timeout) { this->receive_timeo = timeout; }
+    void set_keep_alive(int timeout) { this->keep_alive_timeo = timeout; }
 ...
 }
 ~~~

docs/about-timer.md

@@ -1,6 +1,5 @@
 # 关于定时器
 
-和网络任务，计算任务或文件任务一样，定时器是我们框架中的一种基础任务。  
 定时器的作用是不占线程的等待一个确定时间，同样通过callback来通知定时器到期。
 
 # 定时器的创建