feat: add prevent signature edits example

Author: InosRahul

playground/signatures/prevent-signature-edits/index.ts

@@ -0,0 +1,13 @@
+import type { ImageAnnotation, InkAnnotation } from "@nutrient-sdk/viewer";
+import { baseOptions } from "../../shared/base-options";
+
+window.NutrientViewer.load({
+  ...baseOptions,
+  theme: window.NutrientViewer.Theme.DARK,
+  isEditableAnnotation: (annotation) => {
+    if ("isSignature" in annotation) {
+      return !(annotation as InkAnnotation | ImageAnnotation).isSignature;
+    }
+    return true;
+  },
+}).then(() => {});

playground/signatures/prevent-signature-edits/playground.mdx

@@ -0,0 +1,6 @@
+---
+category: signatures
+title: Prevent Signature Edits
+description: Prevents users from editing or modifying electronic signatures after they have been placed on the document.
+keywords: [signature, read-only, prevent edit, isEditableAnnotation, electronic signatures]
+---