Add API documentation.

index.html

@@ -43,6 +43,19 @@
       {
         text-align: right;
       }
+      table
+      {
+        width: 80%;
+        margin: auto auto;
+      }
+      table caption, table tr:first-of-type td
+      {
+        border-bottom: 1px solid;
+      }
+      table td:first-of-type
+      {
+        border-right: 1px solid;
+      }
     </style>
     <link rel="alternate" type="application/rss+xml" title="The newest FediBlock entries. All tags."
       href="/rss">
@@ -115,6 +128,29 @@
       </li>
     </ul>
 
+    <h2 id="api">API</h2>
+
+    <p>
+      <a href="https://fediblock.org/api/v1/list">https://fediblock.org/api/v1/list</a> returns an array of objects with
+      these properties:
+    </p>
+
+    <table>
+      <caption>Properties</caption>
+      <tr>
+        <td id="property">Property</td>
+        <td id="description">Description</td>
+      </tr>
+      <tr>
+        <td headers="property">instance:</td>
+        <td headers="description">The hostname of the instance.</td>
+      </tr>
+      <tr>
+        <td headers="property">url:</td>
+        <td headers="description">The location of the full data set.</td>
+      </tr>
+    </table>
+
     <h2 id="contact">Contact</h2>
 
     <p>