feat: notify document updates over websocket

apps/server/internal/httpserver/templates/base.gohtml

@@ -27,6 +27,11 @@
         {{ template "error_content" .Data }}
       {{ end }}
     </main>
+    <div class="version-notice" data-version-notice hidden>
+      <p>A newer version is available.</p>
+      <button type="button" data-version-reload>Reload</button>
+    </div>
+    <script src="/static/realtime.js" defer></script>
   </body>
 </html>
 {{ end }}

apps/server/internal/httpserver/templates/document.gohtml

@@ -1,7 +1,7 @@
 {{ define "document.gohtml" }}{{ template "base" . }}{{ end }}
 
 {{ define "document_content" }}
-<article class="document-shell">
+<article class="document-shell" data-document-path="{{ .Path }}" data-document-hash="{{ .Hash }}">
   <div class="document-meta">
     <p class="eyebrow">{{ .Path }}</p>
     <h1>{{ .Title }}</h1>