Warn when precompiling assets in development

[abevoelker]

Per #97 this adds a warning when doing rails assets:precompile in development

I don't know what the preferred wording is, and also the default logging in a fresh Rails 7 app seems to be writing this to log/development.log but not emitting it to the console's STDERR - not sure if that is desirable?

[brenogazzola]

Thanks @abevoelker.

Since the message explicitly uses the word "precompiling" and "serving assets" I'm not sure placing it in the compiler is the best choice. If we have something other the assets:precompile using that method later, the message would not make much sense.

Let's follow the example of the reveal feature and move the message to the task itself and use a standard p. This would ensure it's printed to the terminal and always visible to the developer, even if he chose to have his logs somewhere else.

[abevoelker]

@brenogazzola Thanks, that makes sense. Let me know if the force-pushed change is more like what you were thinking of. Should it be a standard puts like the reveal feature which writes to stdout, or perhaps warn or $stderr.puts that go to stderr since it's a warning? Or perhaps it doesn't matter. At a glance I see a mix in the main Rails code base.