Added guidance for "guide" and "FAQ"

We have a tendency to use these terms in page titles
And we should avoid, for the reasons outlined in this MR

doc/development/documentation/styleguide/word_list.md

@@ -312,6 +312,11 @@ Instead of:
 
 Use **expand** instead of **open** when you are talking about expanding or collapsing a section in the UI.
 
+## FAQ
+
+We want users to find information quickly, and they rarely search for the term **FAQ**.
+Information in FAQs belongs with other similar information, under an easily searchable topic title.
+
 ## field
 
 Use **box** instead of **field** or **text box**.
@@ -367,6 +372,11 @@ Use title case for **GitLab Runner**. This is the product you install. See also
 
 Use **GitLab self-managed** to refer to the product license for GitLab instances managed by customers themselves.
 
+## guide
+
+We want to speak directly to users. On `docs.gitlab.com`, do not use **guide** as part of a page title.
+For example, **Snowplow Guide**. Instead, speak about the feature itself, and how to use it. For example, **Use Snowplow to do xyz**.
+
 ## Guest
 
 When writing about the Guest role: