migrate research writeups from issues

[LordGhostX]

Fix for https://github.com/waku-org/docs.waku.org/pull/163 which migrates the following research writeups:

• https://github.com/waku-org/research/issues/42
• https://github.com/waku-org/research/issues/31
• https://github.com/waku-org/research/issues/23
• https://github.com/waku-org/research/issues/22