If we assign the message (which might contain quotes) to an
environment variable and then echo it, this should prevent the
problem of having a double quote (").
Also fix a problem in docs script for checking TAGs in commits.
- Move directories into more descriptive organization
- src_mdbook, src_markdeep, src_raw
- mdbook will be generated from mdbook
- markdeep will be generated to html
- raw will be copied without modification
- Add script that will run on a succesful commit to main. This
script will update /docs and commit the changes.
- Re-enable docs presbumit check (checks if there has been direct
edits of /docs).
- Fix script to download and install mdbook
- Update Materials.md.html and re-run the build script
(build/run.py).
