Added the dashboard page

src/html/dashboard.html

@@ -0,0 +1,8 @@
+<div id="dashboard" style="display: none">
+  <form>
+    <div class="form-group">
+      <input type="text" class="form-control form-control-sm" id="search-input" placeholder="Recherche" aria-describedby="search-help" autofocus />
+      <small id="search-help" class="form-text text-muted">* parmi les membres, les projets et les groupes de discussion</small>
+    </div>
+  </form>
+</div>