Clarify that “o” refers to Orbiton editor

[jamadagni]

Hello. See the line:

open-in-editor/README.md

Line 40 in e2c2eab

`open-in-editor` looks for any of the following substrings in the path: `emacsclient` (emacs), `subl` (sublime), `charm` (pycharm), `vim` (vim) or `o` (o). For example, any of the following values would work:

Please change the:

`o` (o)

above to:

`o` (orbiton)

… assuming that is the editor you meant.

A hyperlink to https://github.com/xyproto/orbiton would also be appreciated.

Compared to the other editors, I had never heard of any “o” editor, and googling for /usr/bin/o didn't help and only further googling suggested (as the 15th result or so) that the above is probably what you meant because it seems to be useful for terminal/git operations…