Announce Trusted Setup V4 ceremony

[0xjei]

Description

This PR adds the announcement of the MPC Phase 2 Trusted Setup ceremony for Semaphore V4 circuits variants (from 1 up to 32).

Related Issue(s)

see #546

Other information

• The information about the precise dates is NOT present. Therefore, I kindly ask to review styles/aspect and do NOT merge until confirmation of dates!
• A new custom reusable Banner component has been added to the website app. Minor changes have been made to avoid Banner-NavBar overlap.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have run yarn format and yarn lint without getting any errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[cedoor]

LGTM! Just left a comment about CSS