Tweak GitHub issue template

[skip ci]

ISSUE_TEMPLATE.md

@@ -1,5 +1,4 @@
 Make sure you've completed the following steps before submitting your issue -- thank you!
-You can remove this template text afterward.
 
 1. Check if your question has already been answered in the [FAQ](http://pybind11.readthedocs.io/en/latest/faq.html) section.
 2. Make sure you've read the [documentation](http://pybind11.readthedocs.io/en/latest/). Your issue may be addressed there.
@@ -7,11 +6,12 @@ You can remove this template text afterward.
 4. If you have a genuine bug report or a more complex question which is not answered in the previous items (or not suitable for chat), please fill in the details below.
 5. Include a self-contained and minimal piece of code that reproduces the problem. If that's not possible, try to make the description as clear as possible.
 
+*After reading, remove this checklist and the template text in parentheses below.*
 
-#### Issue description
+## Issue description
 
 (Provide a short description, state the expected behavior and what actually happens.)
 
-#### Reproducible example code
+## Reproducible example code
 
 (The code should be minimal, have no external dependencies, isolate the function(s) that cause breakage. Submit matched and complete C++ and Python snippets that can be easily compiled and run to diagnose the issue.)