Promotional banners

[raclim]

Changes:

• Temporary banner randomly promoting either the Processing Fellowships or the UCLA Social Software Summer Institute Art & AI Track. Will be removed on June 1st.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123

[release-com]

Release Environments

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To see the status of the Environment click on Environment Status below.

• p5.js-web-editor
  • app-tedc004.release.editor.p5js.org/
  • preview-tedc004.release.editor.p5js.org/

🔧Environment Status : https://app.release.com/public/Processing%20Foundation/env-db3243a6b7