chore: updated screenshots in README.md and added recent events (#17650)

* chore: updated screenshots in readme.md and added recent events

* chore: updated pinot superset connection instructions

* fixed outdated slack link

* addressed all outstanding feedback!

* updated package lock

* reverted package.json to master

* Update README.md

Co-authored-by: Evan Rusackas <evan@preset.io>

Co-authored-by: Evan Rusackas <evan@preset.io>