Warn on console when a generated migration contains reviewable steps

[joshprice]

Is your feature request related to a problem? Please describe.

Destructive actions are commented out in generated migrations, but it's not clear to the user that something in the migration needs review.

Describe the solution you'd like

Ideally you should always review your migrations, but it'd be great to remind people of this with a note to this effect. Eg

Please always manually review the generated migrations for correctness

When there is something for review we should warn the user more emphatically to do so. Eg

Warning: there are migration steps commented out and in need of manual review

[MaxfieldLewin]

+1; just ran into this and was quite surprised. Coming from Django/Rails, they don't have such strong guardrails for destructive migrations, and it feels a bit overbearing for the generator to assume my changes were erroneous. Not that I don't appreciate the thought! I've seen plenty of migrations gone awry. IMO a sweet spot would be to have the warnings @joshprice suggests and then make it an opt-in configurable behavior to have destructive operations commented out or not.

[joshprice]

I like that idea. Warnings + optional opt out does seem like a good compromise for new users and powerusers alike.