doc: Cleanup of conf.py settings
doc: Cleanup of conf.py settings

We only care about HTML output for now. Remove all the non-HTML builder
configuration.

In addition, the 'html_static_path' and 'templates_path' options
referenced invalid paths. Unset these settings for now.

Signed-off-by: Stephen Finucane <06fa905d7f2aaced6dc72e9511c71a2a51e8aead@that.guru>

getpatchwork/git-pw,stephenfin/git-pw