Feature request: Add `i` modifier

[AlexCid]

First of all, thank you for your awesome project. I really wanted to try helix but could not unlearn VIM keybindings...

Would it be possible to implement the i modifier, so that e.g. ciw / diw commands work as expected in evil-helix ?

Thanks in advance.

[usagi-flow]

That's an excellent suggestion! I'm adding those in a few moments.