add typescript definition file

index.d.ts

@@ -0,0 +1,16 @@
+type ConfigOptions = {
+  quoteMarkdown?: boolean,
+  copyMarkdown?: boolean,
+  scopeSelector?: string
+}
+
+interface Subscription {
+  unsubscribe: () => void
+}
+
+export function install(container: Element, options?: ConfigOptions): void;
+export function uninstall(container: Element): void;
+export function subscribe(container: Element, options?: ConfigOptions): Subscription;
+export function findContainer(el: Element): Element | undefined;
+export function findTextarea(container: Element): HTMLTextAreaElement | undefined;
+export function quote(text: string, range: Range): boolean;

package.json

@@ -4,10 +4,12 @@
   "version": "0.8.2",
   "main": "dist/quote-selection.umd.js",
   "module": "dist/quote-selection.esm.js",
+  "types": "index.d.ts",
   "license": "MIT",
   "repository": "github/quote-selection",
   "files": [
-    "dist"
+    "dist",
+    "index.d.ts"
   ],
   "scripts": {
     "clean": "rm -rf dist",