Fix `vintageous_enter_insert_mode` for NeoVintageous 1.22.0
Fix `vintageous_enter_insert_mode` for NeoVintageous 1.22.0

Fixes #1395

In NeoVintageous/NeoVintageous#749, pushed as 1.22.0 (Oct 2020), the
relevant commands were renamed.

We follow the new names, but for now also call the old ones.

divmain/GitSavvy,divmain/GitSavvy,divmain/GitSavvy