Added sign up and register

Related to: https://gitlab.com/gitlab-org/gitlab/-/issues/352143

doc/development/documentation/styleguide/word_list.md

@@ -683,6 +683,10 @@ Do not use profanity. Doing so may negatively affect other users and contributor
 
 Use lowercase for **push rules**.
 
+## register
+
+Use **register** instead of **sign up** when talking about creating an account.
+
 ## Reporter
 
 When writing about the Reporter role:
@@ -780,6 +784,10 @@ Use **sign in** instead of **sign on** or **log on** or **log in**. If the user
 
 You can use **single sign-on**.
 
+## sign up
+
+Use **register** instead of **sign up** when talking about creating an account.
+
 ## simply, simple
 
 Do not use **simply** or **simple**. If the user doesn't find the process to be simple, we lose their trust. ([Vale](../testing.md#vale) rule: [`Simplicity.yml`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/doc/.vale/gitlab/Simplicity.yml))