fix: restore logo in header with crumb-text layout

Logo img + crumb-text wrapper were missing from the breadcrumb.
Now: logo (32px) on left, $ protocol-droid and crumb path stacked
to its right.

frontend/index.html

@@ -15,8 +15,11 @@
 
 <header>
   <div class="breadcrumb" onclick="navigate('library')">
-    <span><span class="prompt">$</span> protocol-droid</span>
-    <span class="crumb-path" id="crumbPath"></span>
+    <img src="frontend/logo.svg" class="header-logo" alt="">
+    <div class="crumb-text">
+      <span><span class="prompt">$</span> protocol-droid</span>
+      <span class="crumb-path" id="crumbPath"></span>
+    </div>
   </div>
   <nav id="navBar">
     <a href="#library" class="active" data-view="library">PROTOCOLS</a>