Extract CodeMirror language package

packages/decodal-codemirror/README.md

@@ -0,0 +1,54 @@
+# decodal-codemirror
+
+CodeMirror 6 language support for Decodal.
+
+This package provides the Lezer parser metadata, highlighting tags, indentation rules, and block folding used by the Decodal Web playground.
+It does not include the Decodal runtime or WebAssembly evaluator.
+Use `decodal-wasm` when you want to evaluate Decodal in a browser.
+
+## Install
+
+```sh
+npm install decodal-codemirror
+```
+
+JSR:
+
+```sh
+deno add jsr:@hare/decodal-codemirror
+```
+
+## Usage
+
+```js
+import { basicSetup } from 'codemirror';
+import { EditorView } from '@codemirror/view';
+import { decodal } from 'decodal-codemirror';
+
+new EditorView({
+  doc: 'Server = { port = Int default 8080; };',
+  extensions: [
+    basicSetup,
+    decodal(),
+  ],
+  parent: document.querySelector('#editor'),
+});
+```
+
+## Exports
+
+```js
+import {
+  decodal,
+  decodalLanguage,
+  decodalHighlightStyle,
+} from 'decodal-codemirror';
+```
+
+`decodal()` accepts a small options object:
+
+```js
+decodal({ highlight: false })
+```
+
+Use this when you want the language support without the bundled highlight style.