Fix broken links

Author: SteveBarnett

sites/en/frontend/deploying_to_github.step

@@ -1,6 +1,6 @@
 h2 do
   span "If you have already deployed your app to GitHub, go on to "
-  a 'Deploying to GitHub again', href: "deploying_to_github_pages_again"
+  a 'Deploying to GitHub again', href: "deploying_to_github_again"
   span "."
 end
 

sites/en/frontend/deploying_to_github_again.step

@@ -1,6 +1,6 @@
 h2 do
   span "If you haven't deployed your app to GitHub yet, start at "
-  a 'Deploying to GitHub', href: 'deploying_to_github_pages'
+  a 'Deploying to GitHub', href: 'deploying_to_github'
   span "."
 end