* Updates the current stable Ruby version to 2.5.3 and the corresponding link (points to 'downloads' so it's always up to date)
* Adds references to RVN, rbenv
* Cleans up formatting (extra spaces, misplaced periods and commas)
* Adding some more information
Added some explanation about the loops. Make the things a little more easy to understando if you don't have some experience background.
* fix: changed users changes to 2nd person