Update documentation and configuration on how to access community-showcase

[jmunroe]

For team members internal to 2i2c, access to showcase.2i2c.cloud should automatically be granted via helm-charts/basehub/values.yaml

For people not internal to 2i2c, use the GitHub organization https://github.com/2i2c-community-showcase and set up the appropriate teams

• Write up this documentation in team-compass
• Remove the old 2i2c-org/Research-Delight-Team team from config file
• Remove the old 2i2c-org/Research-Delight-Team team from 2i2c-org Github org

[jnywong]

Remove the old 2i2c-org/Research-Delight-Team team from config file

2i2c-org/infrastructure#3700

[jnywong]

Splitting off remaining documentation task into 2i2c-org/team-compass#822 and closing this issue.