Remove build badges from doc page
The main doc page contains badge images showing the license, the CI build status, etc. Lintian complains about them when packaging the docs due to privacy concerns: https://lintian.debian.org/tags/privacy-breach-generic.html Remove the badges from the html docs.
Note: the same badges are still present in the README file, which is rendered in the project page. But this is ok since it is not packaged as html