build: update issue template for bug reports

Author: fengyuanchen

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,73 @@
+name: "\U0001F41E Bug report"
+description: Create a report to help us improve
+body:
+  - type: markdown
+    attributes:
+      value: |
+        **Before You Start...**
+
+        This form is only for submitting bug reports. If you have a usage question
+        or are unsure if this is really a bug, make sure to:
+
+        - Read the [docs](https://fengyuanchen.github.io/viewerjs)
+        - Ask on [GitHub Discussions](https://github.com/fengyuanchen/viewerjs/discussions)
+        - Look for / ask questions on [Stack Overflow](https://stackoverflow.com/questions/ask?tags=viewerjs)
+
+        Also try to search for your issue - it may have already been answered or even fixed in the development branch.
+        However, if you find that an old, closed issue still persists in the latest version,
+        you should open a new issue using the form below instead of commenting on the old issue.
+  - type: input
+    id: version
+    attributes:
+      label: Viewer version
+    validations:
+      required: true
+  - type: input
+    id: reproduction-link
+    attributes:
+      label: Link to minimal reproduction
+      description: |
+        The easiest way to provide a reproduction is by showing the bug in the [Playground](https://fengyuanchen.github.io/viewerjs).
+        If it cannot be reproduced in the playground and requires a proper build setup, try [StackBlitz](https://stackblitz.com/?starters=frontend).
+        If neither of these are suitable, you can always provide a GitHub repository.
+
+        The reproduction should be **minimal** - i.e. it should contain only the bare minimum amount of code needed
+        to show the bug.
+
+        Please do not just fill in a random link. The issue will be closed if no valid reproduction is provided.
+      placeholder: Reproduction Link
+    validations:
+      required: true
+  - type: textarea
+    id: steps-to-reproduce
+    attributes:
+      label: Steps to reproduce
+      description: |
+        What do we need to do after opening your repro in order to make the bug happen? Clear and concise reproduction instructions are important for us to be able to triage your issue in a timely manner. Note that you can use [Markdown](https://guides.github.com/features/mastering-markdown/) to format lists and code.
+      placeholder: Steps to reproduce
+    validations:
+      required: true
+  - type: textarea
+    id: expected
+    attributes:
+      label: What is expected?
+    validations:
+      required: true
+  - type: textarea
+    id: actually-happening
+    attributes:
+      label: What is actually happening?
+    validations:
+      required: true
+  - type: textarea
+    id: system-info
+    attributes:
+      label: System Info
+      description: Output of `npx envinfo --system --npmPackages viewerjs --binaries --browsers`
+      render: shell
+      placeholder: System, Binaries, Browsers
+  - type: textarea
+    id: additional-comments
+    attributes:
+      label: Any additional comments?
+      description: e.g. some background/context of how you ran into this bug.