Debug docs

[rosscastle]

I've created a page for debugging on here rather than the google doc.

Please add your comments, edit what's already been written and add more things. There is no right or wrong really, do not ask people to make changes, just make them yourself if you feel it is needed.

Thanks!

[daw538]

Good start, I've added just a little extra here and there.

I guess there could be a good amount of discussion about what order we'd tend to prioritise the various steps listed. Worth remembering also that the column model isn't currently in the master.

[rosscastle]

Mention the solution found in #80