feat(build): command help

packages/build/build/cli.js

@@ -48,6 +48,7 @@ program
       action,
       args = [],
       description,
+      help,
       name = keys[i],
       options = [],
     } = commands[keys[i]];
@@ -61,6 +62,9 @@ program
       cmd.addOption(options[i]);
     }
     cmd.action(forwardProcessCode(action));
+    if (help) {
+      cmd.addHelpText('after', `\n${help}`);
+    }
   }
   // Parse commandline.
   program.parse(process.argv);

packages/dox/build/commands.js

@@ -79,6 +79,13 @@ module.exports = (program, flecks) => {
         .choices(['build', 'create', 'start']),
       siteDirArgument,
     ],
+    help: [
+      'The `build` and `start` subcommands are sugar on top of the corresponding Docusaurus commands.',
+      '',
+      'The `create` subcommand will create a documentation website starter template for you at `siteDir`',
+      "if `siteDir` doesn't already exist (defaults to `website`). A `docusaurus.config.js`",
+      "starter configuration will also be copied to your `build` directory if it doesn't already exist.",
+    ].join('\n'),
   };
   return commands;
 };