[Debian-med-packaging] Bug#804200: python3-avro: clarify description and relation to Python 3

[Ben Finney]

Package: python3-avro
Severity: minor

The package description could be clarified to more closely follow
Debian packaging guidelines, and make clear this installs a Python 3
library.

-- 
 \        “The right to search for truth implies also a duty; one must |
  `\      not conceal any part of what one has recognized to be true.” |
_o__)                                                 —Albert Einstein |
Ben Finney <ben at benfinney.id.au>