target_to_git: Initial commit

Initial commit of target_to_git recipe. This recipe checks out one
repository, does env setup, and builds, then copies a directory from the
build directory and commits it to another git repository.

Change-Id: I925d97f4d56cdde6be93cfa0226d1ec04302efab
Bug: 471
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/59821
Commit-Queue: Rob Mohr <mohrr@google.com>
Reviewed-by: Ina Huh <ihuh@google.com>
3 files changed