:exclamation: Add END OF LIFE notice to README.md

Remove Travis CI

Remove Bountysource

Update stale.yml

Update Twig URL

Added Temporary PHP 8.0 Notice

Merge pull request #599 from dipohl/patch-1

Update index.md

IRC: Switch from Freenode to Libera.Chat

Create SECURITY.md

Replace Probot Stale with GitHub Action

CONTRIBUTING.md: Rename 'type: Question' label to 'type: Support'

Version 2.1.4

Update Pico::VERSION and Pico::VERSION_ID

Update CHANGELOG.md