[NEW] www/py-flask-babelex: Support i18n/l10n in Flask applications

This is fork of official Flask-Babel extension with following features:

• Possible to use multiple language catalogs in one Flask application;
• Localization domains: your extension can package localization file(s) and use them if necessary;
• Does not reload localizations for each request.

WWW: https://github.com/mrjoes/flask-babelex

PR: 242616
Submitted by: Goran Mekić <mek tilda center>