v0.5 released

v0.5 released !

Changelog:
-new case (1st case, should be easier than the current one) with a document from REDACTED sent to REDACTED
-added an introduction
-added a transition between cases
-added a outro
-REDACTED
-changed background (hope you'll like it!)
-better wording of trials and error
-REDACTED

By the way, Merry Christmas to all!