MCR Membership__c should be Lookup, not M-D

[allisonletts]

I'm working in an org that wants to use this data model within the Customer Communities profile. Membership contact roles for this org need to be shared with a broader group (like corporate memberships). Ideally, we'd use sharing sets for sharing.

In my org, I'm changing the M-D relationship for Membership into a Lookup relationship. It feels a little counterintuitive, but it'll be more flexible.

[allisonletts]

@selfuntitled