chore: update repo description link to `docs.fuel.network`

## Problem Statement

The repo description link has the vercel prefix, whereas the docs are already deployed to [docs.fuel.network](https://docs.fuel.network/docs/intro/what-is-fuel/).


## Proposed solution

Change the link to `docs.fuel.network`.

The issue concerns the FuelLabs/docs-hub repository description rather than a source file; start by opening the repository settings and checking the current description link. Done means the description uses docs.fuel.network and the link resolves to the deployed documentation.

Written by the indexing model from the issue text.