Allow absolute paths to setup folders

[bburns]

ob: why l99 use requires the config to be under setups/ folder? When I use absolute path to the config folder, it should not prepend setups/ which results in setups//some/absolute/path.

bb: the idea was to just keep all configs in the setups folder - but will add 'allow absolute paths' to the tasklist

[MRIIOT]

Where do the changes need to happen?

[bburns]

anywhere the .l99_setup file is referenced - currently it just stores the setup name, eg 'oxbox', not a path

eg

https://github.com/Ladder99/ladder99/blob/main/shell/commands/use#L30-L31

https://github.com/Ladder99/ladder99/blob/main/shell/commands/start#L42-L44

[tukusejssirs]

@bburns, how about we check if a particular env var is set? If it is not set, we use $PWD.

Something like this:

L99_HOME="${L99_HOME:-$PWD}"