Update free-courses-th.md (#9020)
* Update free-courses-th.md
* Update courses/free-courses-th.md
Co-authored-by: Sharan J <50091666+shrn01@users.noreply.github.com>
* alphabetize
Co-authored-by: Eric Hellman <eric@hellman.net>
Co-authored-by: Sharan J <50091666+shrn01@users.noreply.github.com>