Add formatting guide to Bug issue template

.github/ISSUE_TEMPLATE/bug_report.md

@@ -4,5 +4,7 @@ about: Bug report
 
 ---
 
+Please read https://github.com/VCVRack/Rack/issues/730 before posting any code or terminal output.
+
 Operating system(s):
 Version of Rack if using official binary, or commit hash and branch if compiling from source: