Add page: Membership help/faq

[s-taube]

We want to add a Help/Faq page for memberships. We might make something similar to the donations help page.

Per this convo with Jenifer:

I also need to make FAQs/Help for individual memberships, group memberships & EDU memberships.

[s-taube]

@jeniferw let me know what content you want for a help/faq page for memberships, and I can add it to free.law. Adding this to the backlog for now!