feat: add issue template

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,42 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+<!-- Step 1 -->
+
+### [REQUIRED] Describe your environment
+
+- Operating System version: _____
+- Browser version: _____
+- Firebase library (`firebase`, `firebase-admin`, etc...) and version: _____
+- GeoFirestore version: _____
+
+<!-- Step 2 -->
+
+### [REQUIRED] Describe the problem
+
+#### Describe the bug
+
+A clear and concise description of what the bug is.
+
+#### Steps to Reproduce
+
+1. Go to '...'
+2. Click on '....'
+3. Scroll to '....'
+4. See error
+
+#### Relevant Code
+
+Reproduce the issue on StackBlitz and provide your forked URL or provide sample code below
+
+https://stackblitz.com/fork/geofirestore-issue-sandbox
+
+```JavaScript
+// TODO(you): code here to reproduce the problem
+```