With empty selection, put cursor inside new braces, quotes, etc

[AndrewDDavis]

By default, micro automatically closes brackets etc when typed, and places the cursor inside the new brackets.

It would be nice if manipulator functions replicated this functionality for empty selections, or simply deferred to micro's default behaviour for a typed single quote, brace, etc. This way, we can remap keys to the manipulator functions without loss of functionality, e.g.:

{
    "'": "command:squote"
}