Split the "Buildkit" page into subpages. Add sections for "Virtual Desktop" and "nix".
This is a general reorganization of the "tools/buildkit.md" page. The page presents several different options. Changes:
- Add table with a summary of options. Describe compatibility of each.
- Split the existing options out into separate pages ("Apt-get", "Docker", "Vagrant", "Generic"). Add more details for each. Include some common headings.
- Add new pages for "Virtual Desktop" and "nix"
Edited by totten