Allow re-do of last categorisation & reduce number of autos

[RayStick]

Closes #99

• Changed user_categorisation.R so that a user can re-do the last categorisation they made
• Shortened down words in user prompts
• Updated README to reflect the above changes to the code

Closes #96

• Changed domain_mapping.R so that only one ID category is now included in the auto-categorizations. Previously there was 'ALF ID' and 'ID' and the former is SAIL specific. One ID category is simpler and more universal across datasets
• Updated the look-up table in data and data-raw to reflect that there is now only one ID category
• Updated README to reflect the above changes to the code, and explain a bit more about the auto categorizations

Checklist before review:

• Please comment on my PR while it's a draft and give me feedback on the development!
• I added everything I wanted to add to this PR, please review!
• The title of this PR is clear and self-explantory.
• I added any appropriate labels to this PR.

[Rainiefantasy]

I've had a look through the code/changes and they all look great - the plots (although from a previous commit) are a really nice addition, don't remember seeing them in my last demo run!
*edited : I couldn't get the branch to sync on R studio but as per your advice used devtools::load_all() and it's all good now!
I can see the changes, nice addition to allow re-doing of last categorisation 😸

[Rainiefantasy]

Tested and happy with all the changes - let me know if you need any more specific feedback 😸

[RayStick]

Thanks for your review Mahwish - appreciate it!