Broken link in display-version.md

[greenonline]

The link to the display installation instructions at the bottom of display-version.md is broken.

This is because there is a typo in the name of the actual .md file (the 'r' in instructions is missing): https://github.com/eloots/Pi-Akka-Cluster/blob/master/docs/display/display-installation-instuctions.md and the link is spelt correctly: https://github.com/eloots/Pi-Akka-Cluster/blob/master/docs/display/display-installation-instructions.md

The solution is either:

• Correct the spelling of the actual display-installation-instuctions.md file, or;
• Mis-spell the link at the bottom of display-version.md