Update match_qualifier requirements as discussed in #131

Supported match qualifiers MUST be included in property suggestions, see
#131 (comment)

draft/index.html

@@ -512,7 +512,7 @@ <h3>Structure of a Reconciliation Query</h3>
           <dd>A string to indicate how to match the values in <code>v</code>.
             This can be used for general matching relations like "skos:exactMatch", "skos:closeMatch", etc. or for specific features like spatial matching with geo data
             (e.g. containment search with "schema:containsPlace" etc.) or custom matching on date fields (e.g. services supporting the [[EDTF]] specification could use "EDTF:Level-0" etc.
-            To allow discovery of supported qualifiers by clients, services that support <code>match_qualifier</code> SHOULD return the supported <code>match_qualifiers</code> for each property
+            To allow discovery of supported qualifiers by clients, services that support <code>match_qualifier</code> MUST return the supported <code>match_qualifiers</code> for each property
             in their property <a href='#suggest-responses'>suggest responses</a>.</p></dd>
         </dl>
         </dd>