Motivation for this change

The zsh-autosuggestions package provides several configuration options
such as a different highlight style (like fg=cyan which is easier to
read).

With rename.nix the old programs.zsh.enableAutosuggestions is still
functional, but yields the following warning like this during evaluation:

trace: warning: The option `programs.zsh.enableAutosuggestions' defined in `<unknown-file>' has been renamed to `programs.zsh.autosuggestions.enable'.

The module provides the most common zsh-autosuggestions (highlight
style and strategy) as options that will be written into the interactive
shell init (/etc/zshrc by default). Further configuration options can
be declared using the extraConfig attr set:

{
  programs.zsh.autosuggestions.extraConfig = {
    "ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" = "buffer_size";
  };
}

A full list of available configuration options for zsh-autosuggestions
can be viewed here: https://github.com/zsh-users/zsh-autosuggestions/blob/v0.4.3/README.md

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.