Feature request: Custom Proton support about modorganizer2-linux-installer

[rockerbacon]

Currently, the option --protonver can passed to proton-launcher.sh in order to specify which version of proton to use. There are two issues with using this option in this context:

• The current matching pattern requires the custom version to be in a directory whose name is prefixed with "Proton ";
• The forwarding of arguments from Lutris to proton-launcher.sh is only implemeted in 2.4.0 and not present in any stable release;

[rockerbacon]

Added in #35

[rockerbacon]

Released in 2.5.0.
Custom proton versions should be specified using the arguments setting in Lutris. In order to see all options available use the following command:

$HOME/.local/share/modorganizer2/proton-launcher.sh --help

[ajventer]

With 2.6.0 this doesn't work yet:

Could not find proton version matching '5.8-GE-1-MF' in directory '/home/metalpoetza/.steam/steam/steamapps/common/'
You can override the version with parameters now but it doesnt' find custom builds.
That's because the PATH for custom builds it's $HOME/.steam/steam/compatibilitytools.d/{PROTONDIR}

in my case:
$HOME/.steam/steam/compatibilitytools.d/{Proton-5.8-GE-1-MF

So the protonver search should include compatibilitytools.d in it's search path as well in order to provide this feature.