docs(api): Add API routes page

[avj2352]

Checklist

• I have read Contributing > Pull requests

Related issue

Fixes #433

Add documentation on API routes to Tuono Doc site

• Provided example for GET & POST methods
• Provided example for Request based JSON payload & Response based JSON payloads
• Adds new page in tuono.dev doc site

[marcalexiei]

CI is failing and PR title isn't following contributing guidelines.
Please, be so kind to fix it before asking for review / changes.
Once done you can mark the PR as "Ready for review"

Thanks

[avj2352]

Apologies, my bad. I've fixed PR checks. please review

[Valerioageno]

Note: With the documentation, we just have to highlight what the user can do (not drive them with a tutorial like page). Better to remove the all the examples and just give to the user a high level overview on the feature. The API reference section will cover it with more details.

Please after the first overview section just write a simple example to show how to return an object with a GET request.

The page does not need to be long.

Thanks

[Valerioageno]

Could you please move this object to the end of the array so it is the one with the least priority within the Routing section?

[Valerioageno]

We shouldn't reference Next.js

Suggested change

	Just like with [NextJS API routes ](https://nextjs.org/docs/pages/building-your-application/routing/api-routes). Tuono API routes provide a solution to build a public API.
	API routes provide a solution to build a public API with Tuono ⚡.
	Any file inside the folder `src/routes/api` is mapped to `/api/*` path and will be treated as an API endpoint instead of a React route.

[Valerioageno]

Refined in the above comment

Suggested change

Any file inside the folder `src/routes/api` is mapped to the base url as `/api/*` and will be treated as an API endpoint instead of a page. They are server-side only bundles and won't increase your client-side bundle size.

[Valerioageno]

We don't need this section. Users can easily understand that only the HTTP methods can be passed to it with the example

Suggested change

	## HTTP Methods
	Tuono provides the following macros to define HTTP Request Methods
	```rs
	#[tuono_lib::api(GET)]
	#[tuono_lib::api(POST)]
	#[tuono_lib::api(PUT)]
	#[tuono_lib::api(PATCH)]
	#[tuono_lib::api(DELETE)]
	```