CodeMirror 6 Rel language package

This is the official Rel language support package for the CodeMirror editor.

It is based on CM6 language support example and contains:

* The Rel grammar in Lezer format
* The CM6 language pack integration index.ts which exports the required function and LanguageSupport
* Tests are in /test/cases.txt and are wired/ran via mocha
* CM6 consumes the dist/index.js file which contains a "compilation" of the parser and the required LanguageSupport

To build/compile the new dist entries run:

``node
npm run prepare
`

To test:

`node
npm run test
`

Development

For local development and testing you can:

- Install fswatch, then run the following script to auto "prepare", watch and copy to the console code editor folder the rel.ts file:

`
fswatch -or src | xargs -I{} sh -c "npm run prepare && cp dist/index.js /rel.ts"
`

e.g.

`
fswatch -or src | xargs -I{} sh -c "npm run prepare && cp dist/index.js ../../Dev/rai-ux/packages/code-editor/src/rel.ts"
`

- Once the fswatch has generated the output file (rel.ts) import it into consore/code editor via changing the CodeEditor.tsx file rel import. E.g:

`
import { rel } from './rel'; //'@relationalai/codemirror-lang-rel';
`
- If all done correctly on any change to the parser files the code editor would refresh and reflect the changes


Note: Make sure you bump the package.json` version on every release ready for consumption by CM6.