Added section on advantages of inclusion before being asked for it

Co-Authored-By: Clare Macrae <github@cfmacrae.fastmail.co.uk>

Author: KateGregory

resources/inclusion/index.md

@@ -8,6 +8,12 @@ title: Inclusion and Accommodation
 
 Conferences, websites, organizations, and workplaces can unwittingly exclude people who differ from the mainstream. This page collects resources to help include more people by accommodating differences.
 
+## Advantages
+
+Some organisers don't see immediate advantages of making their conferences, web sites, or groups more inclusive. Often they say something like "if someone who needs \[an accomodation\] wants to attend or join, we will do it then." But in many cases the absence (or invisibility) of accomodations is keeping those people from trying to attend or join.
+
+This [Twitter thread by @MalwareTechBlog](https://twitter.com/MalwareTechBlog/status/1213945008174190592) describes a surprising benefit of removing toxic users: a sudden growth in the activity on the server by the "ordinary" users who had been quietly uncomfortable while those users were dominating the discussion. Other pre-emptive accomodations could well yield similar results.
+
 ## General Advice
 
 * [Dos and don'ts on designing for accessibility](https://accessibility.blog.gov.uk/2016/09/02/dos-and-donts-on-designing-for-accessibility/) - UK Government Advice, with posters, for inclusive design of websites and applications