Add issue/feature templates

.github/ISSUE_TEMPLATE/bug_report.md

+---
+name: Bug report
+about: Create a report to help us improve
+
+---
+
+**Describe the bug / 描述bug**
+A clear and concise description of what the bug is. 请清晰和精准地描述bug是什么.
+
+**To Reproduce / 复现方法**
+Please describe the steps to reproduce the behavior. 请描述复现问题的步骤.
+
+**Expected behavior / 期望行为**
+A clear and concise description of what you expected to happen. 请清晰和准确地描述你期望发生什么.
+
+**Versions / 各种版本**
+OS: ... (e.g. linux 2.6.32)
+Compiler: ...  (e.g. gcc 7.1)
+brpc: ... (e.g. master head)
+
+**Additional context / 更多上下文**
+Add any other context or screenshots about the problem here. 这里添加这个问题的更多上下文或截图.

.github/ISSUE_TEMPLATE/feature_request.md

+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+**Is your feature request related to a problem? / 你的功能请求是否与某个问题有关?**
+A clear and concise description of what the problem is. 请清晰和准确地描述那个问题是什么.
+
+**Describe the solution you'd like / 描述你喜欢的解决方法**
+A clear and concise description of what you want to happen. 请清晰和准确地描述你期望发生什么.
+
+**Describe alternatives you've considered / 描述你想到的其他折衷方案**
+A clear and concise description of any alternative solutions or features you've considered. 请清晰和准确地描述你想到的其他折衷方案。
+
+**Additional context / 其他上下文**
+Add any other context or screenshots about the feature request here. 这里可以添加更多上下文或截图.