create bug report template, based on aiohttp bug report template (#661)

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,114 @@
+---
+name: Bug Report
+description: Create a report to help us improve.
+labels: [bug]
+body:
+- type: markdown
+  attributes:
+    value: |
+      **Thanks for taking a minute to file a bug report!**
+
+      ⚠
+      Verify first that your issue is not [already reported on
+      GitHub][issue search].
+
+      _Please fill out the form below with as many precise
+      details as possible._
+
+      [issue search]: ../search?q=is%3Aissue&type=issues
+
+- type: textarea
+  attributes:
+    label: Describe the bug
+    description: >-
+      A clear and concise description of what the bug is.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: To Reproduce
+    description: >-
+      Describe the steps to reproduce this bug.
+    placeholder: |
+      1. Have certain environment
+      2. Then run '...'
+      3. An error occurs.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Expected behavior
+    description: >-
+      A clear and concise description of what you expected to happen.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Logs/tracebacks
+    description: |
+      If applicable, add logs/tracebacks to help explain your problem.
+      Paste the output of the steps above, including the commands
+      themselves and their output/traceback etc.
+    render: python-traceback
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Python Version
+    description: Attach your version of Python.
+    render: console
+    value: |
+      $ python --version
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: aiomysql Version
+    description: Attach your version of aiomysql.
+    render: console
+    value: |
+      $ python -m pip show aiomysql
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: OS
+    placeholder: >-
+      For example, Arch Linux, Windows, macOS, etc.
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Database type and version
+    description: Attach your version of MariaDB/MySQL.
+    render: console
+    value: |
+      SELECT VERSION();
+  validations:
+    required: true
+
+- type: textarea
+  attributes:
+    label: Additional context
+    description: |
+      Add any other context about the problem here.
+
+      Describe the environment you have that lead to your issue.
+
+- type: checkboxes
+  attributes:
+    label: Code of Conduct
+    description: |
+      Read the [aio-libs Code of Conduct][CoC] first.
+
+      [CoC]: https://github.com/aio-libs/.github/blob/master/CODE_OF_CONDUCT.md
+    options:
+    - label: I agree to follow the aio-libs Code of Conduct
+      required: true
+...