Bindable actions for moving by subwords

[AlexWayfer]

Description of the problem or steps to reproduce

Hello!

Atom Editor has nice bindings: Ctrl-Left|Right for moving by words (I can bind this after #79, thanks), but Alt-Left|Right moves by subwords.

What does it mean? There is example with | as cursor:

class FooBar|

After Ctrl-Left:

class |FooBar

After Alt-Left:

class Foo|Bar

Specifications

> micro -version
Version: 1.4.1
Commit hash: 1856891
Compiled on August 10, 2018

OS: Arch Linux
Terminal: fish-shell (?)