Better support for Vue 3.x

src/index.js

@@ -6,8 +6,8 @@ import tokens from './tokens'
 function install (Vue) {
   Vue.directive('maska', directive)
 }
-// Install by default if included from script tag
-if (typeof window !== 'undefined' && window.Vue) {
+// Install by default if included from script tag (only Vue 2)
+if (typeof window !== 'undefined' && window.Vue && window.Vue.use) {
   window.Vue.use(install)
 }
 
@@ -17,6 +17,7 @@ function create (el, options) {
 
 export default install
 export {
+  install,
   create,
   mask,
   directive as maska,