Update instructions for creating gh-pages branch
Adding extra icons (ga & snapshot) to download & docs widgets
Removing zip option from download widget

[Finished #55963742]
reposition maven|gradle switcher [#56070698]
Add syntax highlighting
Move fork ribbon down 2px for better alignment
Merge pull request #1 from philwebb/tweaks

A couple of minor tweaks
Merge branch 'gh-pages' of https://github.com/spring-projects/gh-pages into gh-pages
Add clarification to Quick Start code