Add commit message as param to the git.commit-push-all flow

Looking at the commit-push-all flow, it occurred to me that it's not good practice to commit without a message. I think we should add a String param for the commit message.

**Tests**
Testcases:
* `cocmd run git.commit-push-all`
* `cocmd run git.commit-push-all -m "commit message"`

**Docs**
Requires addition [Here](https://cocmd.org/docs/packages/from_hub/git)

Start with the git.commit-push-all flow and inspect how its parameters are declared and how the commit command is invoked. Run `cocmd run git.commit-push-all` and `cocmd run git.commit-push-all -m "commit message"` to verify both cases, then update the git package documentation at the linked location to describe the parameter.

Written by the indexing model from the issue text.