fdp-primer/editor-config: fix package URLs, and highlight the elisp code

1. There seem to be no package called vim-console or nano-devel in the ports tree, rather it's now just called vim or nano (depending on which one a user will install).

2. Highlight the emacs lisp syntax.

Reviewed by: dbaio
Pull Request: https://github.com/freebsd/freebsd-doc/pull/349
Signed-off-by: rilysh <nightquick@proton.me>