make image paths absolute

_includes/header.html

@@ -2,7 +2,7 @@
   <nav id="navbar">
     <div class="navcontainer">
     <a class="brand-logo" href="{{ site.baseurl }}/">
-      <img src="assets/images/simbricks_logo.svg" alt="SimBricks Logo" id="logo"/>
+      <img src="/assets/images/simbricks_logo.svg" alt="SimBricks Logo" id="logo"/>
     </a>
     <a class="brand" href="{{ site.baseurl }}/">
       SimBricks

_layouts/about.html

@@ -6,7 +6,7 @@ layout: base
 <section class="research">
   <div class="container">
     <div class="research-figure">
-      <img src="assets/images/simbricks_example.svg"
+      <img src="/assets/images/simbricks_example.svg"
         alt="Example of a SimBricks simulation configuration with three
         simulated hosts, a server and two clients. We simulate the server in
         gem5 and connect to an SSD simulated through FEMU and a Corundum FPGA

_layouts/base.html

@@ -44,7 +44,7 @@
         <div class="clear"></div>
         {%- if page.banner -%}
         <div class="banner">
-          <img src="assets/images/{{ page.banner }}">
+          <img src="/assets/images/{{ page.banner }}">
         </div>
         {%- endif -%}
       </header>