* Added the location for the issues
* Added the location for MR's
* I wrote the URL in full because
    * We have a mirror on github, adding the full URL makes it more explicit that MR's need to be done on another repo
    * Advertising GAFAM free platforms ;)
* I also use this MR to start using a develop branch and added this to the README
* I also removed how to install from the web interface because ynh has removed the possibility to add custom lists from the webinterface