This commit introduces two new commands to the `borg` CLI:
- `borg compile`: Compiles a `Borgfile` into a "Terminal Isolation
Matrix" (`.matrix` file). The `Borgfile` format is a simple text file
with `ADD <src> <dest>` instructions.
- `borg run`: Executes a `.matrix` file using `runc`. The command
unpacks the matrix into a temporary directory and then executes `runc
run`.
Tests have been added for both commands, mocking the `runc` execution
to avoid environment dependencies.
