CotEditor Plugin Added

While VS Code is the primary target for this software and repository, we will try to sometimes include plugins for other software on a per-request basis if there is enough interest.
CotEditor is a very lightweight native open-source editor for macOS. It is my go-to for quickly looking up and editing files with syntax highlighting but without the overhead of a full IDE. It is a free, open-source software and super fast to get started with. There is a one-click install available through the Mac App Store. Then follow 30s install instruction in README, and you are good to go!

Major Changes:

• Converted tdb.tmLanguage.json into CotEditor/TDB.yml language syntax definition with a number of necessary simplifications, but the vast majority of functionalities are still covered.

Minor Changes:

• Added description and install instructions in CotEditor/README.md.
• Tested performance across all CotEditor default themes and attached 5 of them to CotEditor/README.md.

Full Changelog: v1.2.1...CotEditor