9 Add Ubuntu launcher

[Fr-Dae]

https://github.com/Fr-Dae/hafen-client/issues/9 https://github.com/EnderWiggin/hafen-client/issues/94

• Creation of standard markdown (md) files to comply with github display standards. (readme with model, licence)

• I created a Debian folder in /src containing a sh script and a launcher shortcut for the desktop (tested and working).

• (I don't know how do that) it is imperative that the /src/Debian/Haven-ender.desktop and /src/Debian/Haven-ender.sh files are placed at the root of the game (where the jar and config sound files are) otherwise the script will not work..

• I recommend deleting old txt files that have become useless.

fix too https://github.com/EnderWiggin/hafen-client/issues/63

[Fr-Dae]

enable the markdown formating and enable the chapter fast navigation