Update OCV page to include the 4 MIPs that need to be voted on

[yamimaio]

Update OCV page to include the 4 MIPs that need to be voted on.

MIP 6, 7, 8, and 9.
Info for titles and link to each can be found here: https://github.com/MinaProtocol/MIPs/tree/main/MIPS