Segregate API docs url/deployment

[arboleya]

Our docs appear on docs-hub in two versions: stable and nightly.

We need to find a way to align that with our API-docs so that merging related PRs to master (and thus re-deploying the app) doesn't risk breaking the links in the stable version of the docs-hub.

We'll go from this:

	Docs	API-docs
nightly	merged	merged
stable	released	merged (1)

To this:

	Docs	API-docs
nightly	merged	merged
stable	released	released (2)

Note

¹ = wrong
² = correct

[nedsalk]

Had a chat with @petertonysmith94 and this is what we came up with:

1. Create two environments on vercel:
   • Nightly, hosted on fuels-ts-docs-api-nightly.vercel.app, and will be updated on every merge to master
   • Production (already existed), hosted on fuels-ts-docs-api.vercel.app, and for which we'll disable branch tracking and update it on every stable release. We'll have to update our release workflow for this to work.
2. Replace all links in our docs with a magic string (e.g. DOCS_API_URL) which must be replaced in all apps consuming the docs:
   • In our vitepress docs:
     • a localhost version of the docs-api when running dev.
     • with an /api endpoint when deploying PR docs. This requires adding the docs-api outputs to docs/dist/api and vite would then be serving them alongside our docs for every PR.
   • In the official docs with the stable link for the stable docs and the nightly link for the nightly docs. This will require work on the docs-hub repo.
   • In our markdown link checker workflow with a localhost url on which we'll serve the docs just for the link checker to pass. This also solves the issue of new links on the api docs failing this workflow because they're not on nightly yet, as now the served localhost docs would be based on the PR and not on master.