Migrate existing SVG assets to particles

[james-nash]

Is your feature request related to a problem? Please describe.
Currently, the gravity-ui-web repo is effectively the "single source of truth" for some SVG assets like:

• The Buildit logotype
• icons used in UIs (e.g. social media icons)
• some auxilliary logos: Wipro & Designit

They should be moved from there into this repo. That way, we can begin to export and publish them into other formats to support platforms beyond just the web.

Describe the solution you'd like

• Add the SVGs into this repo
• Update build & publish scripts so that those SVGs are distributed via the @buildit/gravity-particles NPM package
• Update the gravity-ui-web repo to:
  • Completely remove the migrate SVG files from it
  • Update its build scripts so that it gets its source SVG files from its dependency on @buildit/gravity-particles

[james-nash]

Done by PR #35