Add deprecation notice to pure theme

themes/pure.zsh-theme

+print -P '%F{yellow}'Oh My Zsh pure theme:
+cat <<-EOF
+
+	  The pure theme has been renamed as 'refined' as per the original author's
+	  request. Change your ZSH_THEME to 'refined' to avoid seeing this warning.
+
+EOF
+print -P '%f'
+
+source ${0:h:A}/refined.zsh-theme