Update README.md

Add Ubuntu Guide from idoco#88

README.md

@@ -81,3 +81,71 @@ Currently you can customize all visible texts and the main widget color by setti
   <script id="intergram" type="text/javascript" src="<Server url>/js/widget.js"></script>
   ```
 6. :tada:
+
+### Install on Ubuntu 
+
+Source: https://github.com/idoco/intergram/issues/88
+
+Install on Ubuntu 18.04.4 LTS to run standalone
+(I condense a 14 hour research and headaches into a 5 minutes install)
+
+Make sure you have the latest node.js and npm
+
+Create your bot with @Botfather (/newbot)
+
+add `TELEGRAM_TOKEN` with the value you got from @Botfather in /etc/environment (TELEGRAM_TOKEN="theToken Value")
+
+apt-get update
+
+apt-get install -y curl gnupg2 git build-essential
+
+cd /opt
+
+git clone https://github.com/idoco/intergram
+
+cd /opt/intergram
+
+edit server.js and add the following at the top:
+
+const fs = require('fs') // Required for reading the certificate and key files
+let options = { key: fs.readFileSync("/opt/intergram/key.pem"), cert: fs.readFileSync("/opt/intergram/bundle.crt") };
+
+replace the line
+const http = require ('http').Server(app);
+with
+const http = require ('https').Server(options,app);
+
+change the port as 3000 does not seem to be allowed -i have also added a line to see if we get the TELEGRAM_TOKEN from environment
+http.listen(process.env.PORT || 8443, function(){
+console.log('listening on port:' + (process.env.PORT || 8443));
+console.log(process.env.TELEGRAM_TOKEN);
+});
+
+**IMPORTANT! YOUR CERTIFICATE MUST ALSO CONTAIN THE INTERMEDIATE CERTIFICATE AT THE BOTTOM OTHERWISE THE HOOK WILL NOT WORK**
+SEE https://cubewebsites.com/guides/fix-telegram-webhooks-not-working/
+
+Point the bot webhook to your bot server by making a `GET` request to the following url (just put the address in your browser)
+`https://api.telegram.org/bot<TOKEN>/setWebhook?url=<https://yourServerURL:8443>/hook`
+
+npm install
+
+npm run build
+
+npm start
+
+you should see:
+listening on port:8443
+1xxxxxxxxxxxxxxxxxV10etq-UVxxxxxxxxxxxxxhAIU3XYZtkI
+
+test by navigating on your browser to https://yourServerURL:8443
+you should get the demo page
+
+type /start in your bot in order to get the client-id
+
+in your project:
+window.intergramId = "client-id"
+window.intergramServer = "https://yourServerURL:8443"
+
+<script id="intergram" type="text/javascript" src="yourServerURL:8443/js/widget.js"></script>
+Hope this helps
+