feat: Create a changelog page

[raulb]

Similar to the changelog section that we have on our Meroxa site, the idea here is to have a dedicated page for anything that's adding value to Conduit. This includes features on the main Conduit repository and any other feature released for Conduit connectors.

Something very important to call out is that anything mentioned in the changelog should tie to something the user can use - i.e. something released, not anything that is in progress.