Update Society of Biblical Literature Full Note for 6.1.6

SBL Handbook 6.1.6 recommends using DOI instead of URL if possible. This change checks for DOI variable and prefers it over URL if present.

Author: dhacker29

society-of-biblical-literature-fullnote-bibliography.csl

@@ -990,7 +990,14 @@
           <text macro="archive-note"/>
         </else-if>
       </choose>
-      <text variable="URL"/>
+      <choose>
+        <if variable="DOI">
+          <text variable="DOI" prefix="https://doi.org/"/>
+        </if>
+        <else>
+          <text variable="URL"/>
+        </else>
+      </choose>
     </group>
   </macro>
   <macro name="access">
@@ -1003,7 +1010,14 @@
           <text macro="archive"/>
         </else-if>
       </choose>
-      <text variable="URL"/>
+      <choose>
+        <if variable="DOI">
+          <text variable="DOI" prefix="https://doi.org/"/>
+        </if>
+        <else>
+          <text variable="URL"/>
+        </else>
+      </choose>
     </group>
   </macro>
   <macro name="unsigned-dictionary-note">