I use a xbox 360 controller
Jump - A
Dash - X
Grab wall - RB
If I remember correctly this is what it also was like in Celeste I think its ok with jump and dash on keyboard, but when you also need to press an extra button, and hold it, that gets extra complicated on keyboard imho.
I think a alternative keyboard mapping could be based on FPS controls, like Move - WASD, Jump - Space, Dash - Shift, Grab - Ctrl. Or grab on shift and dash on ctrl or right click.