Update README and CHANGELOG#981

Merged

noplanman merged 2 commits intophp-telegram-bot:developfrom

noplanman:update_readme_changelog

Jul 5, 2019

Commits on Jul 5, 2019

Update readme and SECURITY.md
noplanman
committed
Upgrade changelog and add "Notes" section to make it more useful for external integrations.
noplanman
committed