Optimizing icon platform grouping and guidance for code editing

[soniakaukonen]

• [x] Iconography Figma specifics of use (guidance article)
• [x] Icon svg-cleanup guidance for maintaining code for final svgs on Figma
• [x] Icon platform regrouping proposal
• [ ] Icon platform categories implementation after review

These improvements have been made to ensure that:

• [x] users of Iconography on Figma can navigate the assets with ease and maintenance of Iconography is smooth
• [x] team avoids bottlenecks of submitting not optimized svg files to the platform or reiterating. Goal: document and share svg-cleanup procedure
• [x] categories are not too bulky on the Icon Platform. Example has been taken from Fontawesome to define descriptive terms for icons.
• [x] Review scheduled for Feb 21st.

[soniakaukonen]

Icon guidance: Icon guidance: https://www.figma.com/file/y0O2rda2LSZMPKxyn8fH1h/Icon-Tigers-Conventions?node-id=0%3A1&t=DNYicSDe3mPF7OlN-0

Category enhancement: https://docs.google.com/spreadsheets/d/10tpuMKvZxNiHGfRt0_OVgcHcWLGAKtWY_wr5adWKNP0/edit#gid=0

@egunther39