Add tcmd commands and docs

[comodoro]

Several new TC commands

Description

Just a few commands using keystrokes

How Has This Been Tested

Just rule and docs changes, tested by using

Types of changes

• [x] Docs change / refactoring / dependency upgrade
• [ ] Bug fix (non-breaking change which fixes an issue or bug)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Renamed existing command phrases (we discourage this without a strong rationale).

Checklist

• [x] I have read the CONTRIBUTING document.
• [x] My code follows the code style of this project.
• [x] I have checked that my code does not duplicate functionality elsewhere in Caster.
• [ ] I have checked for and utilized existing command phrases from within Caster (delete if not applicable).
• Navigation commands overwrite application commands? Thought it would be the other way around, because of this tab navigation cannot just be overriden. Besides, tab movement in caster navigation currently uses ctrl+pgup/down. Not sure if it is possible, but switching to ctrl+tab/shift+tab would eliminate the need to override them in tc.
• [x] My code implements all the features I wish to merge in this pull request.
• [x] My change requires a change to the documentation.
• [ x] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• N/A
• [ ] All new and existing tests pass.
• N/A

Maintainer/Reviewer Checklist

• [ ] Basic functionality has been tested and works as claimed.
• [ ] New documentation is clear and complete.
• [ ] Code is clear and readable.