#365 contributing and readme - update Slack location

Now at sqlcommunity.slack.com.

Author: BrentOzar

CONTRIBUTING.md

@@ -10,7 +10,7 @@ First of all, welcome! We're excited that you'd like to contribute. How would yo
 
 Everyone here is expected to abide by the [Contributor Covenant Code of Conduct](#the-contributor-covenant-code-of-conduct).
 
-Wanna do something else, or have a question not answered here? Hop into Slack and ask us questions before you get started. [Join SQLServer.slack.com](https://sql-server-slack.herokuapp.com/), and we're in the [#FirstResponderKit channel](https://sqlserver.slack.com/messages/firstresponderkit/). We welcome newcomers, and there's always a way you can help.
+Wanna do something else, or have a question not answered here? Hop into Slack and ask us questions before you get started. [Get an invite to SQLCommunity.slack.com](https://sqlps.io/slack/), and we're in the [#FirstResponderKit channel](https://sqlcommunity.slack.com/messages/firstresponderkit/). We welcome newcomers, and there's always a way you can help.
 
 ## How to Report Bugs or Request Enhancements
 

README.md

@@ -19,7 +19,7 @@ Only Microsoft-supported versions of SQL Server are supported here - sorry, 2005
 
 Everyone here is expected to abide by the [Contributor Covenant Code of Conduct](CONTRIBUTING.md#the-contributor-covenant-code-of-conduct).
 
-Want to talk to the developers? [Join SQLServer.slack.com](https://sql-server-slack.herokuapp.com/), and we're in the [#FirstResponderKit channel](https://sqlserver.slack.com/messages/firstresponderkit/).
+Want to talk to the developers? [Get an invite to SQLCommunity.slack.com](https://sqlps.io/slack/), and we're in the [#FirstResponderKit channel](https://sqlcommunity.slack.com/messages/firstresponderkit/).
 
 Got a question? Ask it on [DBA.StackExchange.com](http://dba.stackexchange.com). Tag your question with the script name, like sp_Blitz, sp_BlitzCache, sp_BlitzIndex, etc, and we’ll be alerted of it right away.