chore: add an issue form

.github/ISSUE_TEMPLATE/bug-report.yaml

@@ -0,0 +1,43 @@
+name: Bug report
+description: Report a bug of gh-form
+labels:
+  - bug
+  - not reproduced yet
+body:
+  - type: checkboxes
+    id: todo-list
+    attributes:
+      label: Before submitting an issue, make sure that
+      options:
+        - label: You use the latest version of gh-form
+          required: true
+        - label: You have searched for existing issues and confirmed that yours is not a duplicate
+          required: true
+  - type: textarea
+    id: brief-description
+    attributes:
+      label: Brief description of the bug
+      description: Concisely describe the issue you are having.
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction-step
+    attributes:
+      label: Steps to reproduce
+      description: Describe a step-by-step guide to reproduce your bug.
+    validations:
+      required: true
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected result
+      description: What did you expect to happen?
+    validations:
+      required: true
+  - type: textarea
+    id: actual
+    attributes:
+      label: Actual Result
+      description: What actually happened?
+    validations:
+      required: true

README.md

@@ -5,7 +5,6 @@ Don't let malformed issue forms pushed to GitHub
 ## Overview
 
 gh-form enables you to locally preview [YAML-formatted issue forms](https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/syntax-for-issue-forms) as HTML.
-Example below is taken from [TypeScript ESLint](https://github.com/typescript-eslint/typescript-eslint)'s issue template.
 
 ![Screenshot of gh-form's preview](./img/preview.png)