Summary:
- Specify a "position" for the docs/support/blog entries in the top bar.
They had disappeared! This puts them back for some reason.
- Add "Facebook" to the "Social" list in the footer (it's a social
network, right?)
- remove executable permission on some text files (hmmmm)
- rename .md.md file to just .md (this also fixes a dead link)
- update yarn.lock (happened automatically when I tested the website
locally)
Reviewed By: ezgicicek
Differential Revision: D21504931
fbshipit-source-id: 5f89935e2