ENSCORESW-1539: example id set from config

ensembl_rest.conf.default

@@ -130,6 +130,8 @@ jsonp=1
     cdna_coordinates=100..300
     cds_coordinates=1..1000
     translation_coordinates=100..300
+
+    regulation_id=ENSR00001340277
     
     variation_region=9:22125503-22125502:1
     variation_allele=C

root/documentation/regulatory.conf

@@ -10,7 +10,7 @@
       <id>
         type=String
         description=RegulatoryFeature stable ID
-        example=ENSR00001340277
+        example=__VAR(regulation_id)__
         required=1
       </id>
       <species>
@@ -24,7 +24,7 @@
       <basic>
         path=/regulatory/
         capture=human
-        capture=ENSR00001348195
+        capture=__VAR(regulation_id)__
         content=application/json
       </basic>
     </examples>