As we just discussed in IRC, I'd like to add a click-thru prompt for users who are
about to install the MB data via musicbrainz-docker. This click-through prompt should
appear at the start of the installation process where the user will download the data
sets. The message should say the following:

"The data you are about to download is provided by the MetaBrainz Foundation. Are you
planning to use this data for commercial or business purposes? (y/n)"

If the user answers yes, show:

"The MetaBrainz Foundation is supported by commercial users of our data and through
end-user donations. If you are using our data in a commercial context, we require you
to support MetaBrainz financially in order for us ensure the availability of these
datasets in the future." Please sign up at https://metabrainz.org/supporters/account-type ."

[OK]"

If the answer is no, show:

"Could you please sign up at https://metabrainz.org/supporters/account-type (for free!)
so that we may better understand how our data is being used? We also encourage our non-commercial users who can afford it to make a donation to the MetaBrainz Foundation
so that we may continue our mission: https://metabrainz.org/donate .

[ OK ]"