i want to add some features

Dear Nano Development Team,

I am currently working with the Nano text editor and would like to
implement a feature that adds auto-closing for brackets (i.e., `()`, `[]`,
`{}`) and quotes (both single `'` and double `"`). However, I have been
unable to locate the part of the source code that handles user input.

Could someone please guide me to the block or function in the source code
where user input is processed? Any assistance or pointers to the relevant
lines of code would be greatly appreciated.

Thank you for your time and help!