fix: set mode=production by default

[snitin315]

What kind of change does this PR introduce?
bugfix

Did you add tests for your changes?
yes
If relevant, did you update the documentation?
NA
Summary
Resolve #1678

Does this PR introduce a breaking change?
no

Other information

[alexander-akait]

I've always wondered why we have flags --dev/--prod, we already have --mode, it can be misleading for new developers and some of them will be write webpack --prod --mode=production, but it is wrong

[snitin315]

I've always wondered why we have flags --dev/--prod, we already have --mode, it can be misleading for new developers and some of them will be write webpack --prod --mode=production, but it is wrong

It's just alias for --mode=development or production like we have --verbose for --stats=verbose.
CLI throws a warning if user do something like webpack --prod --mode=production
You provided both 'mode' and --prod arguments. You should provide just one. "mode" will be used

[alexander-akait]

I think we should remove them in the future, but it is not high priority

[snitin315]

/cc @webpack/cli-team anyone in favor of --dev and --prod.?

Not a big deal but even if I understand the point of having clean and concise --dev and --prod options, I think the --mode= option better matches the way it works in configuration file and is more straightforward when you already know configuration file. Just my 2 cents, but I'm not sure a breaking change in this area is really useful ?

from feedback too #1222 (comment)

[webpack-bot]

@snitin315 Thanks for your update.

I labeled the Pull Request so reviewers will review it again.

@rishabh3112 Please review the new changes.