Creating SCSS version of all styling

[jodiedoubleday]

What does this PR do? (please provide any background)

• There is a strong demand for scss (sass) UI-Toolkit Elements. Sass is the biggest pre-processor by usage across the web, with PostCSS coming up fast (another PR) so we should cater for these.

  What tests does this PR have?

None

How can this be tested?

You will need to compile the sass files together and generate a css file. We can them apply this css file to our docs and mark down any visual changes that occur.

Screenshots / Screencast

What gif best describes how you feel about this work?

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• [x] I have checked our general contributing document and the project specific contributing document (if present) and I'm happy for this to be reviewed.

  Reviewers

Review 1

• [x] :+1:

Review 2 *

• [x] :+1:

Review 3 (optional)

• [ ] :+1:

By adding a +1 you are confirming you have...

• Witnessed the work behaving as expected (this could be on the author's machine or screencast).
• Checked for coding anti-patterns.
• Checked for appropriate test coverage.
• Checked all the tests are passing.

* for HX this review must be completed by an SE, SA or Project Guru

[elliottcrush]

I like the way you can alter what format of styling you want to wherever your compiling the end result. :+1: