Move Growth page to handbook, add individual growth team vision pages to /direction

source/direction/template.html.md.erb

@@ -115,12 +115,16 @@ groups, again with their own direction pages:
 #### [Geo](/direction/geo)
 #### [Ecosystem](/direction/ecosystem)
-### [Growth](/direction/growth/) Groups
+### Growth Groups
 Supporting the stages in the DevOps lifecycle, there are additional Growth
 groups, again with their own direction pages:
+#### [Acquisition](/direction/acquisition)
+#### [Conversion](/direction/conversion)
+#### [Expansion](/direction/expansion)
 #### [Fulfillment](/direction/fulfillment)
+#### [Retention](/direction/retention)
 #### [Telemetry](/direction/telemetry)
 ## Concepts

source/handbook/engineering/development/growth/index.html.md.erb

@@ -11,9 +11,9 @@ title: Growth Section
 ## Vision
-For more details about the product vision for Growth, see our [Growth] Product Vision page.
-[Growth]: /direction/growth/
+For more details about the product visions of our Growth teams, see our [Growth] Vision pages.
+[Growth]: /direction/#growth-groups
 ## September 2019 Fast Boot

source/direction/growth/index.html.md → source/handbook/product/growth/index.html.md

@@ -15,7 +15,7 @@ The [Growth stage](https://about.gitlab.com/handbook/product/categories/#growth-
 scaling GitLab's business value. To accomplish this, Growth analyzes the entire customer journey from acquisition of 
 a customer to the flow across multiple GitLab features - and even reactivation of lost users. Several groups 
 help with this mission:
-* [Acquisition](https://about.gitlab.com/direction/growth/acquisition/), [Conversion](https://about.gitlab.com/direction/growth/conversion/), [Expansion](https://about.gitlab.com/direction/growth/expansion/) and [Retention](https://about.gitlab.com/direction/growth/retention/) connect users to the existing value that GitLab already delivers by
+* [Acquisition](https://about.gitlab.com/direction/acquisition/), [Conversion](https://about.gitlab.com/direction/conversion/), [Expansion](https://about.gitlab.com/direction/expansion/) and [Retention](https://about.gitlab.com/direction/retention/) connect users to the existing value that GitLab already delivers by
 rapid experimentation.
 * [Fulfillment](https://about.gitlab.com/direction/fulfillment/) ensures a terrific experience throughout the 
 buyer journey for customers doing business with GitLab.