[META] We need a "Using your own data" tutorial

As @sallymatson pointed out, we currently have tutorial style content for all of the steps up to users adding their own data to use with the model. This also seems to be the step that the data team and past Masters students have got stuck on as well. As such we really need a tutorial for this.

Rather than giving instructions to set up each model individually, we should make a generic tutorial. We then want to point users to (informative, well formatted) reference materials which they can use to understand how to setup their specific case. This will require us to improve the quality and formatting of our reference materials as a lot of them are not currently up to scratch.

We also need to make sure that the science models are well described enough that a user can understand exactly what the data they need to add is, i.e. what an animal functional group means etc.

Tutorial content:
#1202
#1203
#1206
#1207
#1208

Improving reference materials:
#1199
#1040
#987
#1037
#1174

Improving explanation of the overall model/individual models
#567
#1210
#1211
#1212
#1213
#1328