docs: point devs to the running-locally guide (#1924)

The token error said "Check the README" but the README had no local
setup instructions, and the running-locally guide pinned the wrong Hugo
version.

- README: add a "Running locally" section linking to the guide
- github-auth.html: point the missing-token error at the running-locally
  guide instead of the README
- running-locally guide: fix Hugo version 0.136.5 -> 0.136.3 to match
  netlify.toml

Co-authored-by: abdishakoor-dev <294276791+abdishakoor-dev@users.noreply.github.com>

Author: abdishakoor-dev

README.md

@@ -34,6 +34,10 @@ Common is tightly integrated with GitHub. Really the main content should always
 
 Each org or team configures its own Hugo site that mounts the common theme and content modules, and then makes any customisations they need and deploys it wherever they want. You can use any repo to do this and your site can be as simple as a `hugo.toml` and a `content/_index.md`. We'd love for you to use Common, too!
 
+## Running locally
+
+To build and run the curriculum on your own machine (install Hugo/Go/npm, create a GitHub token, and start the dev server), follow our [Building the Curriculum Locally](https://curriculum.codeyourfuture.io/guides/contributing/running-locally/) guide. The source for that guide lives at [`org-cyf-guides/content/contributing/running-locally/index.md`](org-cyf-guides/content/contributing/running-locally/index.md).
+
 ## Examples
 
 - https://curriculum.codeyourfuture.io/

common-theme/layouts/partials/github-auth.html

@@ -3,6 +3,6 @@
 {{ if ne $token "" }}
   {{ $headers = dict "headers" (dict "Authorization" (print "Bearer " $token)) }}
 {{ else }}
-  {{ errorf "🏷️ Site needs a HUGO_CURRICULUM_GITHUB_BEARER_TOKEN. Check the README" }}
+  {{ errorf "🏷️ Site needs a HUGO_CURRICULUM_GITHUB_BEARER_TOKEN. See https://curriculum.codeyourfuture.io/guides/contributing/running-locally/" }}
 {{ end }}
 {{ return $headers }}

org-cyf-guides/content/contributing/running-locally/index.md

@@ -14,7 +14,7 @@ Our curriculum is built on top of [Hugo](https://gohugo.io/) and requires some p
 - `npm`
 
 > [!WARNING]
-> We require `v0.136.5-extended` of `hugo` which can be downloaded from [GitHub](https://github.com/gohugoio/hugo/releases/tag/v0.136.5) and manually added to your `$PATH`.
+> We require `v0.136.3-extended` of `hugo` (the version pinned in `netlify.toml`), which can be downloaded from [GitHub](https://github.com/gohugoio/hugo/releases/tag/v0.136.3) and manually added to your `$PATH`.
 > 
 > Later versions will induce an error and building will fail.
 >