Various improvements in the README
Merge "Previewing" with "Dependencies"
Move "Preview Text Changes" under "Translation"
Fix s/bundle exec jekyll/bundle exec jekyll build/
Revert one broken url (Updating English strings)
Shorten instructions as much as possible within three simple steps
Add missing / incomplete instructions for jekyll server
Restore default server port in _config.yml
Add missing "jekyll build" / "jekyll serve" commands
Capitalize all titles consistently