Change default session log directory to ~/.local/state (#859)

This addresses #808 and #823 conclusively for all parties.
- It requires no additional directory creation.
- It does not impact users who do not have a problem.
- It adds additional documentation detail in both the bug template and
the readme to help users who *are* having a problem.
- Fulfills the spirit of the [XDG Spec(https://specifications.freedesktop.org/basedir-spec/latest)
but not in practice as `$XDG_CONFIG_HOME` and `$HOME` and the associated
logic are not implemented. `~/.local/state` is the fallback location.

In particular, the spec indicates:
> It may contain: actions history (**logs**, history, …)

Reviewed-on: https://codeberg.org/fairyglade/ly/pulls/859
Reviewed-by: AnErrupTion <anerruption@disroot.org>
Co-authored-by: Corey Newton <corey.newton@zenoprax.com>
Co-committed-by: Corey Newton <corey.newton@zenoprax.com>

res/config.ini

@@ -285,7 +285,7 @@ service_name = ly
 # Important: due to technical limitations, X11 and shell sessions aren't supported, which
 # means you won't get any logs from those sessions.
 # If null, no session log will be created
-session_log = ly-session.log
+session_log = .local/state/ly-session.log
 
 # Setup command
 setup_cmd = $CONFIG_DIRECTORY/ly/setup.sh