improved toolbar,

implemented filter

src/main/resources/templates/index.html

@@ -14,10 +14,17 @@
         </header>
 
         <section id="tool-bar">
-            <div id="search-bar">
+                <select class="filter-btn">Filter
+                    <optgroup label="Standard categories">
+                        <option>Option 1</option>
+                        <option>Option 2</option>
+                    </optgroup>
+                    <optgroup label="User categories">
+                        <option>user category</option>
+                    </optgroup>
+                </select>
                 <input type="search" name="query" id="search-entry" placeholder="Search">
                 <button class="search-btn">Search</button>
-            </div>
         </section>
 
         <section id="recents">