Savegame Onboarding from current working directory

[OpenBagTwo]

GIVEN Alex is playing a game that she wants to manage with gsb AND she knows where all of the save data lives

WHEN she:

1. Opens a terminal
2. Nagivates to the folder containing her save data
3. Runs the command:

   gsb init my_save_file

   THEN:

4. gsb will create a .git folder in the current working directory
5. gsb will begin tracking my_save_file (and all its contents if it's a directory) but no other files in the directory
6. gsb will create an initial commit and tag it with "Began tracking"

   SO that Alex doesn't need to run the underlying git commands herself (see note)

Notes

So under the hood, the equivalent operations would be:

$ git init
$ echo my_save_file >> .gsb_manifest
$ while read pattern do; git add $pattern; done < .gsb_manifest
$ git commit -m "Start tracking with gsb"
$ git tag -a "v$(date +%Y.%m.%d)" -m "Start tracking with gsb"