Make edit window larger / scrollable.

Hello. Thanks for this technology. It has really helped me. So keep up the good work.

I would like to make a feature request to improve jpterm.

I work with jmespath expressions that span over 100 lines. I'll be writing new ones that will exceed this. To make editing / exploring new expressions easier, I would like the editor window to be larger and scrollable both vertical and horizontal. Certain keystrokes would be nice like beginning of line, end of line, beginning of expression, end of expression, page up/down, goto line in expression, beginning of expression in current line (skip leading whitespaces) And if you can support emacs-like keystrokes for navigation that would be sweet.

But for now, just up/down and right/left arrow keys would be nice.

Thanks and keep up the good work!