Slack invitation redirect

Issue: The slack invite link even set as "do not expire", expires after a certain number of signups

Fix: Update the invite link via Github.

1.  Create a new link. Open your Slack and follow...

1. .   2,

 

3. .  4.

 

5.

2. Got to Github

Got to https://github.com/nycmeshnet/slack-redirect/blob/master/index.html

Create a new PR using the new Slack invite link. Edit line 8 with the new invite link.