Update README to reflect new interface.

README.md

@@ -10,34 +10,37 @@ ktmpl 0.1.0
 Produces a Kubernetes manifest from a parameterized template
 
 USAGE:
-	ktmpl [FLAGS] <template>
+	ktmpl [FLAGS] [OPTIONS] <template> [--]
 
 FLAGS:
     -h, --help       Prints help information
     -V, --version    Prints version information
 
+OPTIONS:
+    -p, --parameter <parameter>...    Key-value pair used to fill in the template's parameters in the format key=value
+
 ARGS:
     <template>    Path to the template file to be processed
 ```
 
 ## Usage
 
-Simply run `ktmpl TEMPLATE` where TEMPLATE is a path to a Kubernetes manifest template in YAML format.
+Run `ktmpl TEMPLATE` where TEMPLATE is a path to a Kubernetes manifest template in YAML format.
 The included [example.yml](example.yml) is a working example template.
 
-To provide values for template parameters, simply execute the program with matching environment variables set.
+To provide values for template parameters, use the `--parameter` option to supply key-value pairs.
 Using the provided example.yml, this would mean:
 
 ``` bash
-MONGODB_PASSWORD=password ktmpl example.yml
+ktmpl example.yml --parameter MONGODB_PASSWORD=password
 ```
 
 Template parameters that have default values can be overridden with the same mechanism.
 
 The processed template will be output to stdout, suitable for piping into a `kubectl` command:
 
 ``` bash
-MONGODB_PASSWORD=password ktmpl example.yml | kubectl create -f -
+ktmpl example.yml --parameter MONGODB_PASSWORD=password | kubectl create -f -
 ```
 
 ## Installing ktmpl
@@ -46,8 +49,9 @@ MONGODB_PASSWORD=password ktmpl example.yml | kubectl create -f -
 
 1. Install the appropriate version of [Rust](https://www.rust-lang.org/) for your system.
 2. Run `git clone [email protected]:InQuicker/ktmpl.git`.
-3. Inside the freshly cloned repository, run `cargo build --release`.
-4. Copy the binary from `target/release/ktmpl` to a directory in your PATH, such as `/usr/local/bin`.
+3. Inside the freshly cloned repository, run `cargo install --path .`.
+
+Make sure Cargo's bin directory is added to your PATH environment variable.
 
 ## Legal