[feature suggest] implement grid-based navigation

[eret9616]

Is your feature suggestion related to a problem? Please describe.
some element cant be selected by homerow

Describe the solution you'd like
implement a grid-based navigation approach

Describe alternatives you've considered
[A clear and concise description of any alternative solutions or features you've considered.]

1. split the screen to grids, e.g. 20x20, 40x40
2. show numbers on each grid
3. press the numbers to focus mouse to a grid

there are some apps like scoot can doing this, but there are some bugs , i hope homerow can add this feature.