`fn processor` not exported publicly even though `enum` might be

[markopesevski]

Hi there! First of all thank you very much for this awesome crate!!

I'm working on a project where the use case of this crate is to have one crate host the CLI definition, which gets used in a different binary crate. With this repo's main branch, we get errors like:

error[E0624]: associated function `processor` is private
 --> examples/desktop-visibility/src/main.rs:8:27
  |
8 |         &mut BaseCommand::processor(|_h, _c| match _c {
  |                           ^^^^^^^^^ private associated function
  |
 ::: /home/marko/git/embedded-cli-rs/examples/desktop-visibility/cli/src/lib.rs:3:17
  |
3 | #[derive(Debug, Command)]
  |                 ------- private associated function defined here

For more information about this error, try `rustc --explain E0624`.
error: could not compile `desktop-visibility` (bin "desktop-visibility") due to 1 previous error

I've created a minimal reproduction repo for this bug, available here: https://github.com/markopesevski/embedded-cli-rs-pub-visibility-demo.

I've also opened a PR #22 for a proposed fix.

[funbiscuit]

Hi! Thanks for detailed explanation and repro. Merged your PR, closing the issue