Added class and os alternates

.oh-my-zsh/plugins/copybuffer/README.md

@@ -0,0 +1,11 @@
+# `copybuffer` plugin
+
+This plugin binds the ctrl-o keyboard shortcut to a command that copies the text
+that is currently typed in the command line ($BUFFER) to the system clipboard.
+
+This is useful if you type a command - and before you hit enter to execute it - want
+to copy it maybe so you can paste it into a script, gist or whatnot.
+
+```zsh
+plugins=(... copybuffer)
+```