Fix capitalization of Github in main content subheader (#8666)

Author: anthonylo87

_guide-pages/2FA.html

@@ -29,7 +29,7 @@
     <div class="section-container">
         <div>
             <h3 class="title-left"><strong>To Enable 2FA:</strong></h3>
-            <h5 class="title-left"><strong>Visit and follow <a href="https://docs.github.com/en/github/authenticating-to-github/configuring-two-factor-authentication" target="blank">Github's Guide to Setting Up 2FA</a></strong></h5>
+            <h5 class="title-left"><strong>Visit and follow <a href="https://docs.github.com/en/github/authenticating-to-github/configuring-two-factor-authentication" target="blank">GitHub's Guide to Setting Up 2FA</a></strong></h5>
         </div>
 
         <div>