Update issue templates

issue模板

.github/ISSUE_TEMPLATE/bug-report.md

+---
+name: Bug report
+about: Describe this issue template's purpose here.
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+<!-- Thank you for using Flutter Boost!
+
+     If you are looking for support about how to get start, please read README first
+-->
+
+## Steps to Reproduce
+**A small application to reproduce the bug(最小化可复现的demo)**
+
+<!--
+     Please tell us exactly how to reproduce the problem you are running into.
+
+     Please attach a small application (ideally just one main.dart file) that
+     reproduces the problem. You could use https://gist.github.com/ for this.
+
+     If the problem is with your application's rendering, then please attach
+     a screenshot and explain what the problem is.
+-->
+
+1. ...
+2. ...
+3. ...
+
+<!--
+     Please tell us which target platform(s) the problem occurs (Android / iOS / Web / macOS / Linux / Windows)
+     Which target OS version, for Web, browser, is the test system running?
+     Does the problem occur on emulator/simulator as well as on physical devices?
+-->
+
+**Flutter Boost Version**
+**Target Platform:**
+**Target OS version/browser:**
+**Devices:**
+
+
+## Logs
+add your crash log or something else.
+
+<!-- Finally, paste the output of running `flutter doctor -v` here. -->
+
+```
+```