[docsy] Missing website files to be copied over from docsy-tuf.io

[chalin]

Originally posted by @chalin in #68 (review):

Note that you'll need to copy over and include the following in this PR

• All of the dot files and folders such as .github, .cspell.yml, etc.
• The LICENSE files
• The updated Makefile
• The updated README.md (keep the current badge)

Tasks:

• Added missing files from docsy-tufio  #77

[chalin]

Closed by #81