doc: add a .nojekyll to gh pages and ignore submodules

Author: cirosantilli

README.adoc

@@ -112,7 +112,7 @@ Related: <<soft-topics>>.
 
 This setup has been tested on Ubuntu 20.04.
 
-The Buildroot build is already broken on Ubuntu 21.04 onwards: https://github.com/cirosantilli/linux-kernel-module-cheat/issues/155[], just use the <<docker>> setup in that case. We could fix it on Ubuntu 21.04, but it will break again inevitably later on.
+The Buildroot build is already broken on Ubuntu 21.04 onwards: https://github.com/cirosantilli/linux-kernel-module-cheat/issues/155[], so just do this from inside a 20.04 Docker instead as shown in the <<docker>> setup. We could fix the build on Ubuntu 21.04, but it will break again inevitably later on.
 
 For other host operating systems see: xref:supported-hosts[xrefstyle=full].
 

publish-gh-pages

@@ -9,10 +9,16 @@ git checkout master -- \
   '*.png' \
   _config.yml \
 ;
+touch .nojekyll
+# submodules are not deleted on checkout.
+# We should not publish like this, we should make a separate tree,
+# otherwise files appear and disapear as you publish, which is bad
+# for editors. But lazy.
+echo 'submodules' >> .gitignore
 cp out/README.html index.html
 cp out/doc/* .
 mv README.html index-split.html
 git add .
-git commit --message "$(git log -n1 --pretty='%H' master)"
-git push
+git commit --allow-empty --message "$(git log -n1 --pretty='%H' master)"
+git push -f
 git checkout -