Atom has recently moved to using Github Discussions as the main message
board for all Atom related stuff. It is important to have all Atom
related conversations on one platform to foster transparency.
Similar to issue #16167 and PR #16173
Change links to `The Atom Flight Manual` and `Atom Slack team` to support SSL/TLS by changing URL to `https://`
[ci skip]
Signed-off-by: U8N WXD <cs.temporary@icloud.com>
