ci: fix broken documenation test (works on RtD) (#2506)

* ci: fix broken documenation test (works on RtD)

* docs: docs link incorrect

.github/workflows/ci.yml

@@ -493,7 +493,7 @@ jobs:
     - uses: actions/setup-python@v2
 
     - name: Install Doxygen
-      run: sudo apt install -y doxygen
+      run: sudo apt-get install -y doxygen librsvg2-bin # Changed to rsvg-convert in 20.04
 
     - name: Install docs & setup requirements
       run: python3 -m pip install -r docs/requirements.txt

README.rst

@@ -147,9 +147,9 @@ file. By using, distributing, or contributing to this project, you agree
 to the terms and conditions of this license.
 
 .. |Latest Documentation Status| image:: https://readthedocs.org/projects/pybind11/badge?version=latest
-   :target: http://pybind11.readthedocs.org/en/master/?badge=latest
+   :target: http://pybind11.readthedocs.org/en/latest
 .. |Stable Documentation Status| image:: https://img.shields.io/badge/docs-stable-blue
-   :target: http://pybind11.readthedocs.org/en/stable/?badge=stable
+   :target: http://pybind11.readthedocs.org/en/stable
 .. |Gitter chat| image:: https://img.shields.io/gitter/room/gitterHQ/gitter.svg
    :target: https://gitter.im/pybind/Lobby
 .. |CI| image:: https://github.com/pybind/pybind11/workflows/CI/badge.svg