add a kinder message up front

Author: jamestalmage

.github/issue_template.md

@@ -2,6 +2,7 @@
 
 ## Prerequisites
 
+- We realize there is a lot of data requested here. We ask only that you do your best to provide as much information as possible so we can better help you.
 - Read the [contributing guidelines](https://github.com/sindresorhus/ava/blob/master/contributing.md).
 - Support questions are better asked in one of the following locations:
   - [Our chat](https://gitter.im/sindresorhus/ava)