docs: fix doxyfile to support functions

Doxyfile

@@ -504,7 +504,7 @@ EXTRACT_ALL            = YES
 # be included in the documentation.
 # The default value is: NO.
 
-EXTRACT_PRIVATE        = NO
+EXTRACT_PRIVATE        = YES
 
 # If the EXTRACT_PRIV_VIRTUAL tag is set to YES, documented private virtual
 # methods of a class will be included in the documentation.
@@ -516,13 +516,13 @@ EXTRACT_PRIV_VIRTUAL   = NO
 # scope will be included in the documentation.
 # The default value is: NO.
 
-EXTRACT_PACKAGE        = NO
+EXTRACT_PACKAGE        = YES
 
 # If the EXTRACT_STATIC tag is set to YES, all static members of a file will be
 # included in the documentation.
 # The default value is: NO.
 
-EXTRACT_STATIC         = NO
+EXTRACT_STATIC         = YES
 
 # If the EXTRACT_LOCAL_CLASSES tag is set to YES, classes (and structs) defined
 # locally in source files will be included in the documentation. If set to NO,
@@ -538,7 +538,7 @@ EXTRACT_LOCAL_CLASSES  = YES
 # included.
 # The default value is: NO.
 
-EXTRACT_LOCAL_METHODS  = NO
+EXTRACT_LOCAL_METHODS  = YES
 
 # If this flag is set to YES, the members of anonymous namespaces will be
 # extracted and appear in the documentation as a namespace called
@@ -769,7 +769,7 @@ SHOW_FILES             = YES
 # Folder Tree View (if specified).
 # The default value is: YES.
 
-SHOW_NAMESPACES        = NO
+SHOW_NAMESPACES        = YES
 
 # The FILE_VERSION_FILTER tag can be used to specify a program or script that
 # doxygen should invoke to get the current version for each file (typically from