Reapplied all the things

package.json

@@ -35,7 +35,7 @@
       "context": "node"
     },
     "test": {
-      "source": [],
+      "source": ["common/tree.test.ts"],
       "outputFormat": "commonjs",
       "isLibrary": true,
       "context": "node"
@@ -54,6 +54,9 @@
     "@fortawesome/fontawesome-svg-core": "1.3.0",
     "@fortawesome/free-solid-svg-icons": "6.0.0",
     "@fortawesome/react-fontawesome": "0.1.17",
+    "@codemirror/highlight": "^0.19.0",
+    "@codemirror/language": "^0.19.0",
+    "@lezer/markdown": "^0.15.0",
     "@jest/globals": "^27.5.1",
     "better-sqlite3": "^7.5.0",
     "body-parser": "^1.19.2",