feat(select_mode): some maps are extended to select mode

[wuelnerdotexe]

Hello! @declancm - first of all thanks for this awesome plugin.

I have tested that some keymaps can also work with Vim --SELECT-- Mode without causing any conflict, so I have enabled them. Tell me if my contribution is acceptable to you. And I also want you to know that I have more contributions in my fork for your wonderful project, if you don't mind getting more pull requests...