feature request: add a recursive flag to the CLI options

[Pomax]

There is currently no option to just run Uglify on a dir and have it replace everything in CLI context. It would be super useful to have a --recursive option so you can just go npx uglify --recursive . and have it do what it needs to do.

[alexlamsl]

Firstly, when you specify multiple input files, uglify-js will concatenate them into a single output file by default.

We do have --in-situ flag on CLI to process and overwrite a list of input files.

We also support glob-style input, e.g. path/to/*.js, for specifying input files.

However they don't current work together, so that we can improve upon.

[Pomax]

awesome, thank you so much for the quick PR!

[Pomax]

Oh: this might still need a small update to the readme and --help texts before "really" considering it closed, since this adds new functionality that should probably be discoverable in the docs as well.

[alexlamsl]

Probably worth a section in README.md mentioning the glob usage etc. − feel free to contribute.

[Pomax]

given the number of projects I'm currently swamped with, and not having written the PR or original docs: you're far more qualified than I am to add that.