cell.csl: Add a macro for DOI and webpage accessed date. (#5999)

cell.csl

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<style xmlns="http://purl.org/net/xbiblio/csl" version="1.0" class="in-text" default-locale="en-US" demote-non-dropping-particle="sort-only" page-range-format="expanded">
+<style xmlns="http://purl.org/net/xbiblio/csl" version="1.0" class="in-text" demote-non-dropping-particle="sort-only" page-range-format="expanded" default-locale="en-US">
   <info>
     <title>Cell</title>
     <id>http://www.zotero.org/styles/cell</id>
@@ -57,6 +57,16 @@
       <label form="short" prefix=", "/>
     </names>
   </macro>
+  <macro name="doi">
+    <choose>
+      <if variable="DOI">
+        <text variable="DOI" prefix="https://doi.org/"/>
+      </if>
+      <else-if type="webpage post post-weblog" match="any">
+        <text variable="URL"/>
+      </else-if>
+    </choose>
+  </macro>
   <citation et-al-min="3" et-al-use-first="1" disambiguate-add-year-suffix="true" collapse="year">
     <sort>
       <key macro="author-short" names-min="1" names-use-first="1"/>
@@ -87,10 +97,13 @@
           <if type="article article-magazine article-newspaper article-journal review" match="any">
             <text variable="title" suffix="."/>
             <text variable="container-title" form="short" text-case="title"/>
-            <group delimiter=", ">
+            <group delimiter=", " suffix=". ">
               <text variable="volume" font-style="italic"/>
               <text variable="page"/>
             </group>
+            <group>
+              <text macro="doi"/>
+            </group>
           </if>
           <else-if type="chapter paper-conference" match="any">
             <text variable="title" suffix="."/>