Include previous connector releases and binaries

[raulb]

On #200, we decided to stop fetching releases before the latest and not include the binaries associated with each one (including the latest in this case).

It's been brought up that, ideally, each connector (either via its own page through connector.yaml or as part of the connectors list page) should contain its history to make navigation to GitHub a priori unnecessary.

What we'll need to do:

• Revert the changes to include all existing releases
• Include the binaries for each release.
• Make sure the dedicated connector page (via connector yaml) includes the same information.

Part of ConduitIO/conduit#1523.