auto update release notes page

[tehlowkeywiz]

https://docs.dfuse.io/eosio/public-apis/release-notes/
https://docs.dfuse.io/eosio/admin-guide/release-notes/

and eventually https://docs.dfuse.io/ethereum/public-apis/release-notes/
https://docs.dfuse.io/ethereum/admin-guide/release-notes/

These should be automatically fetched when we have a new release (or update an already released "release notes" with new notes or corrections). https://github.com/dfuse-io/dfuse-eosio/releases is our single source of truth.

For the Public APIs release notes, everything between # Public API Changes and # System Administration Changes should be included in the release.

For the [System Admin] release notes, everything after # System Administration Changes should be fetched.