Add gr-verilog to CGRAN

[dkozel]

From https://www.cgran.org/submit:

• [ ] Create MANIFEST.md in the root directory of your OOT (example manifest)
• [ ] Create the PyBOMBS Recipe File (.lwr file) instructions at the bottom of this page
• [ ] Add your .lwr file to gr-etcetera in the form of a pull request, look at closed pull requests for examples
• [ ] Once your pull request is merged in, and CGRAN does its daily update, your OOT should show up
• [ ] If your OOT does not seem to show up, check that it is not included in the blacklist located here