fix broken header image by bringing it into selfhosted assets

Author: hjwp

Diff for: images/seagull_nebula_jpl.jpeg

@@ -39,7 +39,7 @@ <h1 class="title">Cosmic Python</h1>
   <div class="row">
     <div class="column">
       <div class="banner-image-container">
-        <img src="https://www.jpl.nasa.gov/spaceimages/images/largesize/PIA13111_hires.jpg" />
+        <img src="/images/seagull_nebula_jpl.jpeg" />
         <div class="banner-text">
           <h1>cosmic_python</h1>
           <h2>Simple patterns for building complex applications</h2>

Diff for: index.html

@@ -4,7 +4,7 @@
   <div class="row">
     <div class="column">
       <div class="banner-image-container">
-        <img src="https://www.jpl.nasa.gov/spaceimages/images/largesize/PIA13111_hires.jpg" />
+        <img src="/images/seagull_nebula_jpl.jpeg" />
         <div class="banner-text">
           <h1>cosmic_python</h1>
           <h2>Simple patterns for building complex applications</h2>

Diff for: pages/index.html

@@ -7,7 +7,7 @@
             Simple patterns for building complex apps
         </description>
         <link>https://www.cosmicpython.com</link>
-        <lastBuildDate>Thu, 05 Nov 2020 21:07:22 -0000</lastBuildDate>
+        <lastBuildDate>Wed, 20 Jan 2021 10:08:39 -0000</lastBuildDate>
         <pubDate>Sat, 4 Jan 2020 19:15:54 -0500</pubDate>
         <atom:link href="https://cosmicpython.com/rss.xml" rel="self" type="application/rss+xml" />