Progress indicator for input dir

[gauntface]

Would the project be open to a PR to add a progress bar to the CLI to show progress through the set of HTML files to minify?

Running on a static site can take considerable time and a progress bar would help affirm that work is on-going and the tool hasn't frozen.

[sibiraj-s]

Might be a good addition I guess. can be enabled with --progress options when working with directories.

Do we need to add a npm dependency for that or we can show a simple message like

Minifying ${filename}. {noOfFiles} completed of total ${totalFiles}

which can be done with few lines of code. 🤔

[DanielRuf]

which can be done with few lines of code.

Less dependencies is better. An option makes sense.