Install the 'ruby-mode' package.
Install the 'ac-math' package.
More quickly start auto-complete and show its menu and quick help.
Move the configuration for ruby-mode to packages.d/init-ruby-mode.el.
Don't complete with the return key.
Re-organize ac-sources.
Install the package 'inf-ruby'.
Move the configuration of org-mode to packages.d/init-org-mode.el.
Setup the org-capture.
Prepend a newly captured entry.
Add global keys for accessing Org commands.
Specify org-agenda-files.