Proper fix for missing node types in web build

Using `path` in web for these cases is ok (but not ideal) because webpack shims it out

extensions/markdown-language-features/tsconfig.json

@@ -2,6 +2,9 @@
 	"extends": "../tsconfig.base.json",
 	"compilerOptions": {
 		"outDir": "./out",
+		"typeRoots": [
+			"./node_modules/@types"
+		],
 		"skipLibCheck": true
 	},
 	"include": [