sopel-rainbow v0.2.0

Changed:

• Dropped support for Sopel<7.1 + Python<3.8
  • sopel.module -> sopel.plugin
  • Removed shim around sopel.formatting.plain() function
  • Updated __future__ imports
  • Removed UTF-8 coding comment

Added:

• Use unicodedata2 if it's installed

Fixed:

• random_start setting (broken by changes in #1)
• Errors in sopel-plugins configure rainbow
  • Wrong setting name (rainbow -> order)
  • Wrong default value type (list[int] -> list[str])

Meta:

• Reorganized to match current Sopel standard (mainly putting "the
  actual plugin" in a plugin.py file, not __init__.py)
• Updated packaging to use pyproject.toml metadata
• Added release automation using PyPI Trusted Publishing