Instructions for downloading and integrating vue-easy-dnd

(Unfortunately we cannot use the latest version, since that requires vue3 support, and bootstrap-vue isn't there yet...)

1. download vue-easy-dnd distribusion throuhg npm
   npm install vue-easy-dnd@1.22.0

2. Copy node_modules/vue-easy-dnd/dist/vue-easy-dnd.esm.js to amd/src/vue-easy-dnd/

3. Change import statements to
   import './reflect-metadata';
   import { Vue, Component, Prop } from './vue-property-decorator';

--- Support libraries ----
This version if vue-easy-dnd requires some additional support libraries in the same folder

-- vue-class-component.js --
1. if not already installed during vue-easy-dnd install, download vue-class-component distribusion through npm
   npm install vue-class-component@7.2.6

2. copy node_modules/vue-class-component/dist/vue-class-component.esm-browser.js to amd/src/vue-easy-dnd/vue-class-component.js

3. change Vue import statement to
   import Vue from '../vue/vue';

4. Replace both export statements at the bottom of the file by the following:
   export { Component, createDecorator, mixins };

-- vue-property-decorator --
1. if not already installed during vue-easy-dnd install, download vue-property-decorator distribusion through npm
   npm install vue-property-decorator@8.5.1

2. copy node_modules/vue-property-decorator/lib/vue-property-decorator.js to amd/src/vue-easy-dnd/

3. change import statements to
   import Vue from '../vue/vue';
   import { Component, createDecorator, mixins } from './vue-class-component';

-- reflect-metadata.js --
1. if not already installed during vue-easy-dnd install, download reflect-metadata distribusion through npm
   npm install reflect-metadata@0.1.13

2. copy node_modules/reflect-metadata/Reflect.js to amd/src/vue-easy-dnd/reflect-metadata.js

3. add the following after the copyright notice:
   export {Reflect};
