Add relationship between Resource Usage Statement and Resource in the…

… md files (#26)

entities/Resource.md

@@ -15,6 +15,9 @@ Anything that can be used for or in the process of research.
 
 <a name="rel__has-identifier">A Resource can *[have](../entities/Resource_Identifier.md#user-content-rel__is-assigned-to)* any number of [Resource_Identifiers](../entities/Resource_Identifier.md).</a>
 
+<a name="rel__used-for-contribution">A Resource can be *[linked with a contribution](../entities/Resource_Usage_Statement.md#user-content-rel__uses)* over [a resource usage statement](../entities/Resource_Usage_Statement.md) which is using the resource. For instance, funding, dataset, or equipment can be used in producing a journal article.</a>
+
+
 ---
 ## Matches
 

entities/Resource_Usage_Statement.md

@@ -11,4 +11,5 @@ statement: [Multilingual String](../datatypes/Multilingual_String.md)
 ## Relationships
 A Resource Usage Statement *[references](../entities/Resource.md)* the [Contribution Statement](../entities/Contribution_Statement.md) that is being used.
 
-A Resource Usage Statement *[references](../entities/Resource.md)* the [Resource](../entities/Resource.md) that is being used. 
+<a name="rel__uses">A Resource Usage Statement *[references](../entities/Resource.md)* the [Resource](../entities/Resource.md#user-content-rel__used-for-contribution) that is being used.</a>
+