cw elaborate on slack channels

source/handbook/tools-and-tips/index.html.md

@@ -91,7 +91,7 @@ Slack now supports "Do Not Disturb Hours" so you won't be pinged in the middle o
 #### Browse Channels
-You can browse all available GitLab channels by clicking on "Channels" on the left pane in the Slack app. From there, you can see every channel, who created it, and how many members there are.
+You can browse all available GitLab channels by clicking on "Channels" on the left pane in the Slack app. From there, you can see every channel, who created it, and how many members there are. Every team member is automatically added to `#general`, where announcements are made and information for the entire company is shared. There are also a few default channels that every new hire is added to, such as: `#celebrations`, `#new_labbers`, `#questions`, `#random`, `#thanks`, & `#working-on`; these channels are optional, but we think they are a great place for team members to interact and get to know each other.
 #### Slack Status
@@ -392,7 +392,7 @@ your e-mail ([STEP 2](#change-username-step-2)), which will be different
 **STEP 1: Request your new username**
 - Access the username you want to request via `https://gitlab.com/mary`.
-- Check its activity and projects to see if he/she is an inactive user 
+- Check its activity and projects to see if he/she is an inactive user
 [according to the handbook](/handbook/support/policies/#dormant-usernames).
 - Send your request to `support@gitlab.com`, explaining the reasons why
 you need that username.