Update issue templates

.github/ISSUE_TEMPLATE/bug_report.md

+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Started loki (SHA or version)
+2. Started promtail (SHA or version) to tail '...'
+3. Query: `{} term`
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Environment:**
+ - Infrastructure: [e.g., Kubernetes, bare-metal, laptop]
+ - Deployment tool: [e.g., helm, jsonnet]
+
+**Screenshots, promtail config, or terminal output**
+If applicable, add any output to help explain your problem.