Implement TextEditor search API in InkTerminal
Implement TextEditor search API in InkTerminal

This allows calling "Find" from the Julia Console, using the standard
find-and-replace package! :)

It's currently just searching a dummy `TextBuffer` that contains `"HI
IT'S NATHAN"`. The next step is to hook it up to the actual xterm.js
Terminal's search capability.

JunoLab/atom-ink