[doc] family limits docs (#5268)

docs/docs/photos/features/family-plans.md

@@ -22,6 +22,25 @@ In brief,
 - You can invite 5 family members. So including yourself, it will be 6 people
   who can share a single subscription, paying only once.
 
+## Storage Limits
+
+If you're an admin of a family, you will be able to set storage limits  for the 
+members in your family plan.
+
+In brief, 
+
+- For example, once you set a limit of 10GB for a member, their Storage
+  quota for uploading photos will be limited to 10GB.
+
+- Once the invited member accepts the Family invite, you will be able to see 
+  an edit icon in the Members List. Click on it to setup a family limit.
+
+- If the admin has set a limit for any user, that limit value will be prefilled
+  in the input box. 
+
+- Incase, if you want to remove any storage limit from a members account, you 
+  can click on the "Remove Limit" and they can upload photos without any limit. 
+
 ## FAQ
 
 - **Can you assign a storage quota for each individual member in the family