[Docs]: Update slack link on Github landing page

[stibrewa]

Issue Description

I created this issue to update the link on our GitHub landing page agntcy/blogs#86, reposting here, since not sure where to create it.

Prposed Solution

I created an issue to update the link on our GitHub landing page agntcy/blogs#86, reposting here, since not sure where to create it.

Affected Component

CSIT

Checklist

• I have read the contributing guidelines.
• I have verified this does not duplicate an existing issue.