Steps to Reproduce

1. Click the Documentation menu option
2. Notice you're over at https://coder.com/docs

Expected

1. We have somewhere that we can link to (what TBD) ✔️
2. This link is updated to point to that placeholder for v2 docs (or the real docs themselves)

Spec

1. We will just link to /docs directory of this very repository
2. We will add an environment variable in webpack, something like CODER_VERSION or similar. If the environment variable is set, use that. Otherwise use main as the default. See Environment Plugin:

   coder/site/webpack.common.ts

   Lines 10 to 18 in 4efde58

   	/**
   	* environmentPlugin sets process.env.* variables so that they're available in
   	* the application.
   	*/
   	const environmentPlugin = new EnvironmentPlugin({
   	INSPECT_XSTATE: "",
   	})
   	console.info(`--- Setting INSPECT_XSTATE to '${process.env.INSPECT_XSTATE || ""}'`)
   	console.info(`--- Setting NODE_ENV to '${process.env.NODE_ENV || ""}'`)

3. The link can then be https://github.com/coder/coder/tree/<CODER_VERSION>/docs