Update index.html.md.erb

Author: stevenjmesser

source/index.html.md.erb

@@ -7,6 +7,6 @@ weight: 1
 
 <%= warning_text('This is a prototype.') %>
 
-This is a reference guide for who we are and the way we do things. It's a playbook for anyone in the GOV.UK Design System team that tells us the 'right way' to do things.
+This is a reference guide for who we are and the way we do things. It's a playbook for anyone in the GOV.UK Design System team that tells us the 'right way' to do things. It's currently in alpha, meaning that contributions from the team are welcome and encouraged!
 
-What's written here is the way we do things now, but that will change from time to time.
+What's written here is the way we do things now, but that will change from time to time.