Merge pull request #1255 from ClickHouse/bug_report_template

add a bug report template

Author: zhicwu

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,35 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+<!-- delete unnecessary items -->
+### Describe the bug
+
+### Steps to reproduce
+1.
+2.
+3.
+
+### Expected behaviour
+
+### Code example
+```java
+```
+### Error log
+
+### Configuration
+#### Environment
+* Client version:
+* Language version:
+* OS:
+
+#### ClickHouse server
+* ClickHouse Server version:
+* ClickHouse Server non-default settings, if any:
+* `CREATE TABLE` statements for tables involved:
+* Sample data for all these tables, use [clickhouse-obfuscator](https://github.com/ClickHouse/ClickHouse/blob/master/programs/obfuscator/Obfuscator.cpp#L42-L80) if necessary