Add README note about local dev

Signed-off-by: lucperkins <[email protected]>

docs/README.md

@@ -84,6 +84,14 @@ make serve
 Open your browser to http://localhost:1313 to see the site running locally. The docs
 are available at http://localhost:1313/docs.
 
+> The local version of the site is different from the production site at
+> https://openpolicyagent.org in important ways. When running the site locally,
+> the documentation you'll see is from the current branch, not from any past release.
+> Thus, there is no version selector or concept of documentation versions in the
+> "dev" site. The documentation that you see when running the site locally will be
+> visible on the production site only when that documentation has been included as
+> part of an OPA release.
+
 ## Site updates
 
 The OPA site is automatically published using [Netlify](https://netlify.com). Whenever

docs/layouts/partials/home/banner.html

@@ -4,8 +4,8 @@
 {{ $tagline     := site.Params.tagline }}
 {{ $socialMenu  := site.Menus.social }}
 {{ $latest      := index site.Data.releases 0 }}
-{{ $docs        := cond $localMode "foo" "bar" }}
-{{ $getStarted  := cond $localMode "/docs/get-started" (printf "/docs/%s/get-started" $latest) }}
+{{ $docs        := cond $localMode "/docs" (printf "/docs/v%s" $latest) }}
+{{ $getStarted  := cond $localMode "/docs/get-started" (printf "/docs/v%s/get-started" $latest) }}
 <header role="banner">
   <nav class="nav--banner" role="navigation">
     <ul class="nav--menu">
@@ -72,4 +72,4 @@ <h1 class="headline--title">
     <div class="headline--wave--bg" role="presentation"></div>
     <div class="headline--wave--fg" role="presentation"></div>
   </div>
-</header>
+</header>