• Local external configuration/hacking: (GIT_XY_ENV_FILE, defaults to git_xy.env)
• Allow to refine rsync command (via git_xy_rsync in GIT_XY_ENV_FILE)

The last option of the configuration now accepts any rsync options (--delete, --verbose). This makes the script works the same way rsync command works, and we don't need to introduction any special syntax to branch name.

The script can also read configuration file stdin. This allows some dynamic feature at the runtime. E.g, when you want to generate Pr for some feature branch (Using configuration requires branch names to be fixed names.)

It's almost working. Need more tests, more documentation (how to set up gh authentication)