Clarify

Author: michaelklishin

deps/rabbitmq_management/priv/www/api/index.html

@@ -986,9 +986,16 @@ <h2>Reference</h2>
         <td></td>
         <td class="path">/api/health/checks/certificate-expiration/<i>within</i>/<i>unit</i></td>
         <td>
-          Checks the expiration date on the certificates for every listener configured to use TLS.
-          Responds a 200 OK if all certificates are valid (have not expired),
-          otherwise responds with a 503 Service Unavailable.
+          <p>
+            Checks the expiration date on the certificates for every listener configured to use TLS.
+            Responds a 200 OK if all certificates are valid (have not expired),
+            otherwise responds with a 503 Service Unavailable.
+          </p>
+          <p>
+            Valid units: days, weeks, months, years. The value of the <i>within</i> argument is the number of
+            units. So, when <i>within</i> is 2 and <i>unit</i> is "months", the expiration period used by the check
+            will be the next two months.
+          </p>
         </td>
       </tr>
       <tr>