Add another note about command modules

Author: Anand Thakker

Diff for: lib/commands/build.js

@@ -51,8 +51,7 @@ function build(documentation, parsedArgs, callback) {
     hljs: options.hljs || {}
   };
 
-  var generator = documentation.bind(null,
-    inputs, options, onDocumented);
+  var generator = documentation.bind(null, inputs, options, onDocumented);
 
   function onDocumented(err, comments) {
     if (err) {

Diff for: lib/commands/index.js

@@ -1,8 +1,12 @@
 /*
  * Maps command name to a command plugin module.  Each command plugin module
- * should export a function that takes (documentation, parsedArgs), where
+ * must export a function that takes (documentation, parsedArgs), where
  * documentation is just the main module (index.js), and parsedArgs is
  * { inputs, options, command, commandOptions }
+ *
+ * Command modules should also export a `description`, which will be used in
+ * the main CLI help, and optionally a `parseArgs(yargs, parentArgv)` function
+ * to parse additional arguments.
  */
 
 module.exports = {