add url params info in docs

Author: michaljaz

docs/DEVELOPMENT.md

@@ -26,11 +26,31 @@ Connect to http://localhost:8080 in your browser. Also specify correct server ip
 npm run build
 ```
 
-After calling this, it will build app bundle with minified code (in ```/src/dist/``` directory). It may take longer than development setup. By default webmc connects to https://webmcproxy.glitch.me.
+After calling this, it will build app bundle with minified code (in ```/src/dist/``` directory). It may take longer than development setup.
 
 Then you have to host built files on some simple http server like [http-server](https://www.npmjs.com/package/http-server).
 
-You can also setup your own proxy server. First of all install only production depencies by running ```npm install --only=production```. Then, all you have to do is to run  ```npm run proxy``` on server and change some configs in ```/src/assets/config.json```.
+## How works webmc url params?
+
+### ?nick=
+
+Minecraft user nickname
+
+### ?server=
+
+It is just server ip like "serverip.eu" or "serverip.eu:25565"
+
+### ?proxy=
+
+Here are webmc proxy options in ?proxy=[string] url param:
+
+- ```production``` default production option, server: https://webmcproxy.glitch.me
+- ```local``` default local-dev option, server: localhost
+- ```[server_hostname]:[port]``` custom proxy server (sometimes ssl certs might not work)
+
+## Own proxy server
+
+You can also setup your own proxy server. It is just translates Websocket connection to TCP connection. You don't need to install all the depencies, just the ones you need. First of all install only production depencies by running ```npm install --only=production```. Then, all you have to do is to run  ```npm run proxy``` on server and change some configs in ```/src/assets/config.json```. Sometimes it is also useful to swap the "proxy" script with "start" in package.json (your app will run proxy by default).
 
 ## Download production files