Enable automated import of release documentation into OSI sphinx documentation

[vkresch]

Describe the feature

The release documentation is currently manually copied into the OSI documentation which needs to be automated.

Describe the solution you would like

Enable automatically release parsing into the documentation from releases.

Describe alternatives you have considered

Alternative would be to maintain two seperate release documentation. The simple one on github and the more detailed one in the documentation if parsing is not possible.

[stefancyliax]

We moved away from sphinx to build the document. General idea is still valid. Keeping this open.