enhancing dodo.py for better automation. Fixes T847
    
    Summary: This improves support for building documentation and putting both docs and released files (rpms, tarballs etc.) in a place that can be publicly accessible so that we can decrease the number of manual steps in our release process (some of which have a tendency to be forgotten)
    
    Test Plan: `dodo basedir=<some output dir> envtype=ci chainbuild`, also run the commands `releasedocs` and `updatelatest`. This will output the docs and release bits into the specified directory.
    
    Reviewers: mkrizek, kparal
    
    Subscribers: jskladan
    
    Differential Revision: https://phab.qadevel.cloud.fedoraproject.org/D1012