Some small revisions

Working-on-Chrome-OS.md

@@ -1,6 +1,11 @@
 ## Setting up the development environment
 Chrome OS does not have a Linux console by default, but one can be installed via settings. To get started, open the Settings app and scroll down. Then expand the advanced options and scroll down until you see the Developers header. Below there should be an option to activate the Linux development environment. Once you click this button you will be prompted to enter a username and a size to allocate for linux. The default 10Gb should be enough.
 
+After having set up the development environment you will need to make sure your packages are up to date first by running these commands.
+
+    sudo apt-get update
+    sudo apt-get upgrade
+
 #### Install required tools
 You need a **GCC** (or alternative C99 compiler) and **make**. Git should be automatically installed.
 
@@ -12,6 +17,7 @@ Optionally, you could use **CMake** building system.
 
 #### Install required libraries
 For raylib to compile, you will need some additional libraries installed
+
     sudo apt install mesa-common-dev libx11-dev libgl1-mesa-dev
 
 ### Build raylib using make