[BUG] Readme "register-here" link for slack is broken

[schenksj]

Bug

Clicking the "register-here" link results in a "This link is no longer active" error:

Describe the problem

Clicking the "register-here" link results in a "This link is no longer active" error, preventing new enrollments though that channel.

Steps to reproduce

1. Visit the readme
2. Click "Register-Here"
3. Feel disappointed

Observed results

Expected results

Further details

Environment information

• Delta Lake version:
• Spark version:
• Scala version:

Willingness to contribute

The Delta Lake Community encourages bug fix contributions. Would you or another member of your organization be willing to contribute a fix for this bug to the Delta Lake code base?

• Yes. I can contribute a fix for this bug independently.
• Yes. I would be willing to contribute a fix for this bug with guidance from the Delta Lake community.
• No. I cannot contribute a bug fix at this time.

[scottsand-db]

cc @dennyglee

[scottsand-db]

cc @MrPowers @nkarpov

[MrPowers]

Thanks @scottsand-db, I opened an issue here to address this one.