use our own input method in vscode

The lean one was annoying for \{...}

playground/src/abbrev.ts

@@ -0,0 +1 @@
+../../newt-vscode/src/abbrev.ts

playground/src/main.ts

@@ -6,6 +6,7 @@ import { h, render } from "preact";
 import { ChangeEvent } from "preact/compat";
 import { archive, preload } from "./preload.ts";
 import { CompileReq, CompileRes, Message } from "./types.ts";
+import { ABBREV } from "./abbrev.ts";
 
 // editor.(createModel / setModel / getModels) to switch files
 
@@ -221,17 +222,6 @@ interface EditorProps {
   initialValue: string;
 }
 
-const ABBREV: Record<string, string> = {
-    '\\x': '×',
-    '\\r': '→',
-    '\\all': '∀',
-    '\\\\': '\\',
-    '\\==': '≡',
-    '\\circ': '∘',
-    '\\1': '₁',
-    '\\2': '₂',
-  }
-
 function Editor({ initialValue }: EditorProps) {
   const ref = useRef<HTMLDivElement>(null);
   useEffect(() => {