We do this since the redis package is soon to be deprecated:
https://lists.archlinux.org/archives/list/arch-dev-public@lists.archlinux.org/thread/2ERGX565GSSBUMADBG7DQJYNPJD5GUXD/



Signed-off-by: Christian Heusel <christian@heusel.eu>

- Add `ft=systemd` where needed
- Remove `ft=` where filetype detection works (especially jinja.vim)
- Set `sw=2 sts=-1 et` everywhere

For symmetry with synapse-worker@.service.

Add federation_reader as a another worker.

Apparently 1.0 is about 3-4G max, which is too much, while 0.1 is about
~700M. Set it to the default of 0.5.

We've seen matrix.archlinux.org dip deep into swap.

The default cache size factor is 0.5.