Corrected errors on gbg page

Author: delphidabbler

_software/gbg.html

@@ -51,7 +51,7 @@ <h2 class="panel-title">
       Creates a file that is 20MiB in size made up of entirely random data.
     </p>
     <p>
-      For more information about on how to use the program see the <a href="https://github.com/ddabapps/gbg/blob/master/README.md">Read Me <span class="sr-only">Markdown </span> file</a> on GitHub.
+      For more information about on how to use the program see the <a href="https://github.com/ddabapps/gbg/blob/main/README.md">Read Me <span class="sr-only">Markdown </span> file</a> on GitHub.
     </p>
     <p class="callout callout-info">
       <span class="fa fa-copyright fa-pull-left fa-3x"></span><em>GBG</em> is copyright &copy; {{ page.copyright-date}} by <a href="{{ site.data.core.gravatar-url }}" aria-label="{{ site.data.core.gravatar-link-title }}">Peter Johnson</a>. The program and its source code are released under the terms of the <a href="https://delphidabbler.mit-license.org/{{page.copyright-date}}-/">MIT License</a>.
@@ -100,10 +100,10 @@ <h2 class="panel-title">
     </p>
     <ul class="list-group">
       <li class="list-group-item">
-        <span class="fa fa-fw fa-x-pad-right fa-file-text-o" aria-hidden="true"></span><a href="https://github.com/ddabapps/gbg/blob/master/README.md">Read Me<span class="sr-only"> (Markdown file)</span></a> &ndash; contains general information about the program, including usage information.
+        <span class="fa fa-fw fa-x-pad-right fa-file-text-o" aria-hidden="true"></span><a href="https://github.com/ddabapps/gbg/blob/main/README.md">Read Me<span class="sr-only"> (Markdown file)</span></a> &ndash; contains general information about the program, including usage information.
       </li>
       <li class="list-group-item">
-        <span class="fa fa-fw fa-x-pad-right fa-file-text-o" aria-hidden="true"></span><a href="https://github.com/ddabapps/gbg/blob/master/CHANGELOG.md">Change Log<span class="sr-only"> (Markdown file)</span></a> &ndash; lists significant changes made in each program release.
+        <span class="fa fa-fw fa-x-pad-right fa-file-text-o" aria-hidden="true"></span><a href="https://github.com/ddabapps/gbg/blob/main/CHANGELOG.md">Change Log<span class="sr-only"> (Markdown file)</span></a> &ndash; lists significant changes made in each program release.
       </li>
     </ul>
   </div>