added an issue template for github.

Author: agentzh

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,27 @@
+This place is for bug reports and development discussions only. For general questions and
+discussions, please join the openresty-en mailing list instead: https://openresty.org/en/community.html
+
+Ensure you have provided the following details while reporting a problem:
+
+* The exact version of the related software, including but not limited to the OpenResty version
+(if any), the NGINX core version, the ngx_lua module version,
+and your operating system version.
+
+* A minimal and standalone test case that others can easily run on their side and
+reproduce the issue you are seeing.
+
+* Do not simply say "something is broken" or "something does not work". Always provide
+as much details as possible. Always describe the symptoms and your expected results.
+
+* You can (temporarily) enable the nginx debugging logs to see the internal workings
+of NGINX in your nginx''s C<error.log> file. See http://nginx.org/en/docs/debugging_log.html
+The same instructions apply equally well to OpenResty.
+
+* If you are seeing crashes, please provide the full backtrace for the crash. See
+https://www.nginx.com/resources/wiki/start/topics/tutorials/debugging/#core-dump
+for more details.
+
+Please, do not use Chinese here. This place is considered English only. If you
+really want to use Chinese, please join and post to the openresty (Chinese)
+mailing list instead. Please see https://openresty.org/en/community.html Thanks for
+your cooperation.