Project specific custom commands

I have a custom command called `test`. I generally keep re-writing when I switch from codebase to codebase. We could potentially have a project specific list of custom commands.

### Approach

- The project can be scoped based on the git root. If its not a git tracked directory, it can assume the current directory as the root
- We don't have to store the custom command files in the project directory. We can still store it in the same custom directory path. We can just add a prefix of the project name to the files to identify them. This way, we can toggle this feature on/off without loosing the commands. When toggled on, the custom commands should only list the project specific ones. When toggled off, it should list all commands

The issue names no files or tests. Start by locating how custom commands are stored, listed, and scoped, then inspect how the project’s Git root could be determined. Done means project-specific commands persist outside the project directory, can be toggled on or off, and listing shows either scoped or all commands as specified.

Written by the indexing model from the issue text.