Add flow def

Author: muan

index.js.flow

@@ -0,0 +1,12 @@
+/* @flow strict */
+
+declare module '@github/remote-input-element' {
+  declare export default class RemoteInputElement extends HTMLElement {
+    get input(): ?HTMLInputElement;
+    get resultsContainer(): ?HTMLElement;
+    get src(): string;
+    set src(url: string): void;
+    get name(): string;
+    set name(value: string): void;
+  }
+}

package.json

@@ -13,8 +13,8 @@
     "clean": "rm -rf dist",
     "lint": "github-lint",
     "prebuild": "npm run clean && npm run lint && mkdir dist",
-    "build-umd": "BABEL_ENV=umd babel index.js -o dist/index.umd.js",
-    "build-esm": "BABEL_ENV=esm babel index.js -o dist/index.esm.js",
+    "build-umd": "BABEL_ENV=umd babel index.js -o dist/index.umd.js && cp index.js.flow dist/index.umd.js.flow",
+    "build-esm": "BABEL_ENV=esm babel index.js -o dist/index.esm.js && cp index.js.flow dist/index.esm.js.flow",
     "build": "npm run build-umd && npm run build-esm",
     "pretest": "npm run build",
     "test": "karma start test/karma.config.js",