Custom bindings for builtin sections

[gbcreation]

Is your feature request related to a problem? Please describe.

I would like to use my own bindings for builtin sections.

Describe the solution you'd like

Add a bindings option to each builtin sections (like custom sections), allowing to define bindings to call functions provided by a builtin section. It would require to expose functions for all operations that can be performed.

Describe alternatives you've considered

A possible alternative would be to have an option to map existing bindings to new ones.

For example, binding <CR> to e in the Buffers section would allow to open the buffer using the Enter key.