[RFC] August Newsletter

This is the August newsletter.

#### Sources for info:

- [ ] Neovim Wiki history
- [ ] Commit history
- [ ] @philix's [Evernote](https://www.evernote.com/shard/s102/sh/86b655b1-c7eb-4822-8423-99130ad1b877/5485150b94f0a23bb378cdac47ecf983)
- [ ] Issue tracker