MIDI player in Frescobaldi wiki page

[Federico Bruni]

Hi folks

A quick email, as I have few time.

While looking at this bug:
https://github.com/wbsoft/frescobaldi/issues/463

I found the link to this wiki page I wrote almost two years ago:
https://github.com/wbsoft/frescobaldi/wiki/MIDI-playback-on-Linux

There are a couple of edits I'd like to do, but I'd like to have some 
feedback from you first.

1. Do not use ~/.config/NAME.desktop to start the MIDI synth
I would remove that section, as you cannot easily control 
applications/services started this way.

2. Suggest only Systemd instead.
I don't know why I wrote that systemd timidity service would have 
worked only if Pulseaudio was not installed. The link which should 
explain it does not work anymore. But anyway I have Pulseaudio 
installed and the timidity service is working fine.

I would add also an example for fluidsynth.

The following works for me:

$ systemctl --user cat fluidsynth.service
# /home/fede/.config/systemd/user/fluidsynth.service
[Unit]
Description=Fluidsynth
After=sound.target

[Service]
ExecStart=/usr/bin/fluidsynth -a pulseaudio -m alsa_seq -i -l -s -p 
FluidSynth -R 0 -C 0 -c 2 -z 512 -r 48000 
/usr/share/soundfonts/default.sf2

[Install]
WantedBy=default.target