Provide more explicit information about ORCID on the write-a-PRErevie…

…w start page

During a user test, we witnessed a user clicking on 'ORCID iD' and expecting to see the sign-in form. I'm not sure how common this will be, but to try and avoid this in the future, this changes the link text to be a question instead ('What is an ORCID iD?').

Refs nhsuk/nhsuk-service-manual-community-backlog#169 (comment)

assets/style.css

@@ -303,6 +303,10 @@ summary {
   touch-action: manipulation;
 }
 
+dfn {
+  font-style: normal;
+}
+
 sub {
   vertical-align: baseline;
   font-size: 50%;

src/write-review.ts

@@ -996,10 +996,16 @@ function startPage(preprint: Preprint) {
 
         <h2>Before you start</h2>
 
-        <p>
-          We will ask you to log in with your <a href="https://orcid.org/">ORCID&nbsp;iD</a>. If you don’t have an iD,
-          you can create one.
-        </p>
+        <p>We will ask you to log in with your ORCID&nbsp;iD. If you don’t have an iD, you can create one.</p>
+
+        <details>
+          <summary>What is an ORCID&nbsp;iD?</summary>
+
+          <p>
+            An <a href="https://orcid.org/"><dfn>ORCID&nbsp;iD</dfn></a> is a persistent digital identifier you own and
+            control, distinguishing you from every other researcher.
+          </p>
+        </details>
 
         <a href="${format(logInMatch.formatter, {})}" role="button" draggable="false">Start now</a>
       </main>