Adding TS typings.

index.d.ts

@@ -0,0 +1,23 @@
+declare module 'find-up' {
+    export interface FindUpOptions {
+        readonly cwd?: string
+    }
+
+    /**
+     * Finds the file and then returns it its path
+     *
+     * @param filename Of the path to be find
+     * @param options Contains the directory to start from
+     * @returns The filepath
+     */
+    export function sync(filename: string | string[], options?: FindUpOptions): string | null;
+
+    /**
+     * Finds the file and then returns it its path
+     *
+     * @param filename Of the path to be find
+     * @param options Contains the directory to start from
+     * @returns The filepath
+     */
+    export default function findUp(filename: string | string[], options?: FindUpOptions): Promise<string | null>;
+}

package.json

@@ -4,6 +4,7 @@
 	"description": "Find a file or directory by walking up parent directories",
 	"license": "MIT",
 	"repository": "sindresorhus/find-up",
+	"types": "index.d.ts",
 	"author": {
 		"name": "Sindre Sorhus",
 		"email": "sindresorhus@gmail.com",
@@ -16,7 +17,8 @@
 		"test": "xo && ava"
 	},
 	"files": [
-		"index.js"
+		"index.js",
+		"index.d.ts"
 	],
 	"keywords": [
 		"find",