Documentation: ignore files from theme
Documentation: ignore files from theme

Fixes the following warning

	_themes/sphinx_rtd_theme/README.rst: WARNING: document isn't included in any toctree
	_themes/sphinx_rtd_theme/tests/roots/test-basic/index.rst: WARNING: document isn't included in any toctree
	_themes/sphinx_rtd_theme/tests/roots/test-empty/index.rst: WARNING: document isn't included in any toctree
	_themes/sphinx_rtd_theme/tests/roots/test-missing-toctree/index.rst: WARNING: document isn't included in any toctree

Signed-off-by: Alexander Alemayhu <e46fc836cca3acec03944314d1457c2ae6c68ef3@alemayhu.com>

michi-covalent/cilium,scanf/cilium,tgraf/cilium,tklauser/cilium,scanf/cilium,scanf/cilium,tgraf/cilium,cilium-team/cilium,tklauser/cilium,eloycoto/cilium,tgraf/cilium,cilium/cilium,scanf/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,eloycoto/cilium,michi-covalent/cilium,scanf/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,cilium-team/cilium,eloycoto/cilium,eloycoto/cilium,eloycoto/cilium,eloycoto/cilium,tgraf/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium,tklauser/cilium,eloycoto/cilium,tklauser/cilium,scanf/cilium,scanf/cilium,cilium/cilium