Added a note about core dumps

ISSUE_TEMPLATE.md

@@ -1,6 +1,12 @@
+Describe what issue you are experiencing. Attach any information that could be helpful in debugging the issue (screen shots, log messages etc).
+
 Please attach output of generate_system_report.sh skript when reporting new issues.
 ```
 export DISPLAY=:0.0
 ./generate_system_report.sh
 ```
-Also include any additional information (screen shots, log messages, etc) that could help with identifying and resolving the issue.
+
+If you're reporting a crash in vaapidevice (e.g. a segmentation fault) then please attach backtrace (command `bt`) from gdb.
+
+Sections 1-4 of the following tutorial can be helpful in first generating a meaningful core dump and then printing a backtrace from it.
+http://www.brendangregg.com/blog/2016-08-09/gdb-example-ncurses.html