FEATURE/MAJOR: Add a bash script to show the matrix

If you don't use Linux... you should ! You're in a engineering
school for f***'s sake !!!
FEATURE/MINOR: Add a welcome message + how to exit
FEATURE/MEDIUM: Add a message to show for how long you used the script
BUG/MEDIUM: Fix wrong duration in ending message

Count only from the start of the "matrix" display.
BUG/MINOR: Add a few newlines before ending message

Improved readability.
Merge branch 'dev/cpe/matrix'

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