Merging and the art of the pull request

[rmbielby]

Cover instructions for the following tasks in the logbook:

• Create a pull request on GitHub
• Solve merge conflict 1
• Solve merge conflict 2
• Solve merge conflict 3

The first one can just be a couple of pull requests involving the branches from the previous stages in the logbook. Those shouldn't throw any conflicts.

I'm then thinking we create some set merge conflict branches (that have branch protections), that people create their own branches from and then go demo manufactured conflicts. So for each merge conflict, we need 2 demo branches, with conflict files in.