fix: Escape regex for embeds (#3907)

Fixes #3899

shared/editor/embeds/JSFiddle.test.ts

@@ -0,0 +1,11 @@
+import JSFiddle from "./JSFiddle";
+
+describe("JSFiddle", () => {
+  const match = JSFiddle.ENABLED[0];
+
+  test("to not be enabled for invalid urls", () => {
+    expect("https://jsfiddleenet/go/share/c9d837d74182317".match(match)).toBe(
+      null
+    );
+  });
+});