Add GDPR requirements to the project whitelist page

[gridcat]

As was mentioned here https://github.com/gridcoin-community/Gridcoin-World-Site/pull/19#discussion_r773936343 it is worth to have GDPR requirements listed.

• Extend the https://gridcoin.world/whitelist.htm page, add GDPR requirements per project.
• Create About GDPR section at the bottom of the page
• Extend the Guides page and refer to the newly created section from the solo crunching guide from the "Choose Projects" section.