v0.2.0

Features

• add standalone executable in AppImage and .exe format
  for Linux and Windows platforms
• show last transmitted usage statistics in admin settings

Bugfixes and other improvements

• replace bootstrap-toc dependency by tocbot
• bump Flask-HTTPAuth from 4.7.0 to 4.8.0
• fix python linting issues (flake8)
• fix JS linting issues (eslint)
• add loading animation for AJAX views
• show API token on user profile
• refactor CSS
• use celery for sending emails
• improve devcontainer setup and automatic server
  reload in development configuration
• remove unused plugin feature

Security patches

• bump cryptography from 41.0.4 to 41.0.6
• bump pillow from 9.5.0 to 10.0.1
• bump urllib3 from 1.26.15 to 1.26.18
• bump werkzeug from 2.2.3 to 3.0.1
• bump jquery from 1.11.3 to 3.5.1 in /js
• bump tough-cookie from 4.1.2 to 4.1.3 in /js
• bump word-wrap from 1.2.3 to 1.2.5 in /js
• bump semver from 7.5.0 to 7.5.4 in /js