Add overview

Specifications/Resource Relation.md

 
-Question: Why are we using resource name instead of doing a join to the related constellation via ic_id? Does
-related_resource_name exist for performance reasons?
+### Overview
+
+Archival resources as described in the CPF resourceRelation should have more data than captured by
+EAC-CPF. SNAC had begun this work by adding an <objectXMLWrap> to the resourceRelation. This XML snippet
+contained some <mods> or a fragment of <ead>. The data includes details about the resource and it's holding
+institution.
 
+### Description of new fields and tables
 
+We will add fields to table related_resource, and (perhap?) create new table related_resource_name.
+
+Question: Why are we using resource name instead of doing a join to the related constellation via ic_id? Does
+related_resource_name exist for performance reasons?
 
 
 Resource language is a many-to-one. Use a reverse foreign key from the multiple records in the language