Clarify how to reach out to CSMs

It was brought up in the AMER skip level this week that it's not super clear how/when/where to reach out to CSMs.

a couple times where I’ve had a customer that just really seems to need PS engagement, or maybe even just their CSM [to have a call] about what their architecture is [and to have the CSM realign with them on goals]. And there’s not a super clear path to get that help.

There’s a workflow page on sales escalations that says you can tag the CSM in slack but…. where? What info do they need? It’s not very clear? [...] this isn’t the first time I’ve been in a “how call in the sales friends as backup” in a ticket and just not found clear answers. I know we can tag in CSMs, but it’s not always clear how best to do so.

Proposal

Review workflow pages and update handbook.

Possible flow:

1. Add CSM to CC if not already there, and notify customer you've done so.
2. Add an internal note on the ZD ticket on why you're adding the CSM if not fully covered in your latest public reply.
3. Notify the CSM via Slack:
   1. If there is an existing thread with an ongoing conversation, ping the CSM to add them.
   2. If no existing thread, look for a customer channel, which should be in the format #a_customerName-internal to start a new thread, pinging the CSM.
   3. If no customer channel, you can start a thread in #spt_managers, #support_gitlab-com, or #support-self_managed.

MR submitted: gitlab-com/content-sites/handbook!541 (merged)