Add gitpod.

.gitpod.yml

@@ -0,0 +1,13 @@
+tasks:
+  - init: |
+      docker-compose build --pull webdav
+    command: |
+      docker-compose up -d webdav
+  - init: |
+      npm install
+    command: |
+      npm run watch
+
+ports:
+  - port: 8080
+    onOpen: open-preview

README.md

@@ -32,6 +32,13 @@ language in [UI.js](src/lib/UI/UI.js).
 
 ## Implementations
 
+### Gitpod demo
+
+[Available here](https://gitpod.io/#https://github.com/dom111/webdav-js), wait for the Docker build to complete, and you
+will be able to interact with the Apache demo, make changes and contribute!
+
+[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/dom111/webdav-js)
+
 ### Bookmarklet:
 
 `javascript:["https://cdn.jsdelivr.net/gh/dom111/webdav-js/assets/css/style-min.css","https://cdn.jsdelivr.net/gh/dom111/webdav-js/src/webdav-min.js"].forEach((function(e,s){/css$/.test(e)?((s=document.createElement("link")).href=e,s.rel="stylesheet"):(s=document.createElement("script")).src=e,document.head.appendChild(s)}));`