feat: Add Fastify reference docs

[LekoArts]

Important

🔎 Previews:

• https://clerk.com/docs/pr/1869
• https://clerk.com/docs/pr/1869/quickstarts/fastify
• https://clerk.com/docs/pr/1869/references/fastify/overview

Explanation:

• Add Fastify to the /docs index page inside the "Backend framework" section
• Add Fastify reference documentation
• Add Fastify to sidebar
• Update Fastify quickstart to put one heading into reference docs

Checklist

• I have clicked on "Files changed" and performed a thorough self-review
• I have added the "deploy-preview" label and added the preview link(s) to this PR description
• All existing checks pass

[github-actions]

Hey, here’s your docs preview: https://clerk.com/docs/pr/1869

[victoriaxyz]

Hi @LekoArts! Looks good. I reorganized the methods, rewrote intros to code examples, added clearer titles. See here: eda1863

Let me know what you think!

[LekoArts]

Thanks for the edit, makes sense! I copied some sentences from https://github.com/clerk/clerk-docs/blob/main/docs/references/express/overview.mdx so we could also carry over those improvements into #1880 if you have to touch that file anyways.

[victoriaxyz]

@LekoArts Updated this PR: 2493658

Thanks for the edit, makes sense! I copied some sentences from https://github.com/clerk/clerk-docs/blob/main/docs/references/express/overview.mdx so we could also carry over those improvements into #1880 if you have to touch that file anyways.

Updated: 547ebef

[alexisintech]

can we get Fastify get added as an option in the dropdown in the Clerk Dashboard?

[alexisintech]

I've committed my final review!

• moved the getAuth() example into a partial so that we can use it in the quickstart and the overview
• moved clerkOptions into a partial to use in both the backend sdk docs (where we document createClerkClient options) and the fastify overview (where we document the clerkPlugin options)
• deleted docs/backend-requests/handling/js-backend-sdks.mdx - I'm just not sure why this guide got created. it seems like repetitive information that doesn't deserve a separate guide. if users need to see how to make requests using one of the sdks, they can go to that sdk's reference docs...
• Quickstart doc:
  • aligned copy with the copy used in other quickstarts, such as "Run the following command to install the SDK:"
  • updated the section title "Use getAuth() to access the auth state and protect routes" to "Protect your routes using getAuth()" to match other quickstarts (express also has a section titled Protect your routes using requireAuth())
  • added missing info about introducing the getAuth() helper, as this will be the first time user's are coming across this helper, we should explain what it is/does before showing an example.
  • added the getAuth() partial
• Overview doc:
  • removed "methods" heading, as its unnecessary and we don't do this anywhere else.
  • moved sections around to make more sense. the structure is now as follows:
    • introduce clerkplugin
      • examples of how to register it
      • clerkplugin() options
        • example of how to use options
    • getauth()
• updated the fastify repo to align with the docs

[victoriaxyz]

can we get Fastify get added as an option in the dropdown in the Clerk Dashboard?

@LekoArts, in case you missed this comment.

[LekoArts]

Sure, I can add it 👍 But that shouldn't block this PR, right? I assume we can merge it now?

Edit: Done: https://github.com/clerk/dashboard/pull/4424