Promote the Docker image as a simple way to install YLT

Dockerfile

@@ -1,7 +0,0 @@
-FROM    node:10
-WORKDIR /app
-ENV     VERSION=master
-EXPOSE  8383
-RUN     git clone --branch ${VERSION} https://github.com/LumberjackOtters/YellowLabTools ylt && cd ylt && yarn install && yarn build
-ENV     NODE_ENV=production
-CMD     ["node", "/app/ylt/bin/server.js"]

README.md

@@ -19,19 +19,20 @@ Analyzes a webpage and detects **performance** or **front-end code quality** iss
     </tr>
     <tr>
         <td width="70%">
-            The <b>CLI</b> (Command Line Interface) - <a href="https://github.com/YellowLabTools/YellowLabTools/wiki/Command-Line-Interface" target="_blank">Doc here</a>
+            The <b>Docker image</b> - <a href="https://github.com/ousamabenyounes/docker-yellowlabtools" target="_blank">ousamabenyounes/docker-yellowlabtools</a>
+            <br>
+            Your own private instance of Yellow Lab Tools, on your computer.
         </td>
         <td width="30%">
-            <img src="./doc/img/YLT-cli-animated.gif"></img>
+            <img src="./doc/img/docker-logo.png"></img>
         </td>
     </tr>
     <tr>
         <td width="70%">
-            The <b>Grunt task</b>: <a href="https://github.com/gmetais/grunt-yellowlabtools" traget="_blank">gmetais/grunt-yellowlabtools</a>
+            The <b>CLI</b> (Command Line Interface) - <a href="https://github.com/YellowLabTools/YellowLabTools/wiki/Command-Line-Interface" target="_blank">Doc here</a>
-            <br>For developers or Continuous Integration
         </td>
         <td width="30%">
-            <img src="./doc/img/grunt-logo.png"></img>
+            <img src="./doc/img/YLT-cli-animated.gif"></img>
         </td>
     </tr>
     <tr>
@@ -65,18 +66,17 @@ By the way, it's free because I am a geek, not businessmen. In return, you can a
 ![example dashboard screenshot](./doc/img/screenshot.png)
 
 
-## Test your localhost
-
-You can use [ngrok](https://ngrok.com/), a tool that creates a secure tunnel between your localhost and the online tool (or the public API). You can also use the CLI or the Grunt tasks as they run on your machine.
-
-
 ## Install your own private instance
 
-If your project is not accessible from outside, or if you want to fork and improve the tool, you can build your own instance. The documentation is [here](https://github.com/YellowLabTools/YellowLabTools/wiki/Install-your-private-server).
+If your project is not accessible from outside or if you want to test your localhost, you might want to run your own instance of Yellow Lab Tools.
+
+The classical way is to clone the project's GitHub repository and run it on Linux of MacOS. The documentation is [here](https://github.com/YellowLabTools/YellowLabTools/wiki/Install-your-private-server).
+
+The new recommended solution is to run Yellow Lab Tools inside a Docker virtual machine. My friend Ousama Ben Younes maintains [this ready-to-use Docker image based on Alpine](https://github.com/ousamabenyounes/docker-yellowlabtools)).
 
 
 ## Author
-Gaël Métais. I'm a webperf freelance. Follow me on Twitter [@gaelmetais](https://twitter.com/gaelmetais), I tweet about Web Performances, Front-end and new versions of YellowLabTools!
+Gaël Métais. I'm a webperf freelance. Follow me on Twitter [@gaelmetais](https://twitter.com/gaelmetais), I tweet about Web Performances, Front-end and new versions of Yellow Lab Tools!
 
 <a href='https://ko-fi.com/gaelmetais' target='_blank'><img height='35' style='border:0px;height:46px;' src='https://az743702.vo.msecnd.net/cdn/kofi3.png?v=0' border='0' alt='Buy me a coffee' /><a>
 

Vagrantfile

@@ -1,24 +0,0 @@
-Vagrant.configure("2") do |config|
-
-  config.vm.box = "ubuntu/trusty64"
-
-  config.vm.network :private_network, ip: "10.10.10.10"
-  config.ssh.forward_agent = true
-
-  # http://foo-o-rama.com/vagrant--stdin-is-not-a-tty--fix.html
-  config.vm.provision "fix-no-tty", type: "shell" do |s|
-    s.privileged = false
-    s.inline = "sudo sed -i '/tty/!s/mesg n/tty -s \\&\\& mesg n/' /root/.profile"
-  end
-
-  config.vm.provider :virtualbox do |vb|
-    vb.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
-    vb.customize ["modifyvm", :id, "--memory", 1024]
-    vb.customize ["modifyvm", :id, "--cpus", 2]
-  end
-
-  config.vm.synced_folder "./", "/space/YellowLabTools"
-
-  config.vm.provision :shell, :path => "server_config/server_install.sh"
-
-end