feat: add English language policy and GitHub issue templates (#534)

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,100 @@
+name: Feature Request
+description: Suggest a new feature or enhancement for oh-my-opencode
+title: "[Feature]: "
+labels: ["enhancement", "needs-triage"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        **Please write your issue in English.** See our [Language Policy](https://github.com/code-yeongyu/oh-my-opencode/blob/dev/CONTRIBUTING.md#language-policy) for details.
+
+  - type: checkboxes
+    id: prerequisites
+    attributes:
+      label: Prerequisites
+      description: Please confirm the following before submitting
+      options:
+        - label: I have searched existing issues and discussions to avoid duplicates
+          required: true
+        - label: This feature request is specific to oh-my-opencode (not OpenCode core)
+          required: true
+        - label: I have read the [documentation](https://github.com/code-yeongyu/oh-my-opencode#readme)
+          required: true
+
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem Description
+      description: What problem does this feature solve? What's the use case?
+      placeholder: |
+        Describe the problem or limitation you're experiencing...
+        Example: "As a user, I find it difficult to..."
+    validations:
+      required: true
+
+  - type: textarea
+    id: solution
+    attributes:
+      label: Proposed Solution
+      description: Describe how you'd like this feature to work
+      placeholder: |
+        Describe your proposed solution in detail...
+        Example: "Add a new hook that..."
+    validations:
+      required: true
+
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives Considered
+      description: Have you considered any alternative solutions or workarounds?
+      placeholder: |
+        Describe any alternative solutions you've considered...
+        Example: "I tried using X but it didn't work because..."
+
+  - type: textarea
+    id: doctor
+    attributes:
+      label: Doctor Output (Optional)
+      description: |
+        If relevant to your feature request, run `bunx oh-my-opencode doctor` and paste the output.
+        This helps us understand your environment.
+      placeholder: |
+        Paste the output of: bunx oh-my-opencode doctor
+        (Optional for feature requests)
+      render: shell
+
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional Context
+      description: Any other context, mockups, or examples
+      placeholder: |
+        Add any other context, screenshots, code examples, or links...
+        Examples from other tools/projects are helpful!
+
+  - type: dropdown
+    id: feature-type
+    attributes:
+      label: Feature Type
+      description: What type of feature is this?
+      options:
+        - New Agent
+        - New Hook
+        - New Tool
+        - New MCP Integration
+        - Configuration Option
+        - Documentation
+        - Other
+    validations:
+      required: true
+
+  - type: checkboxes
+    id: contribution
+    attributes:
+      label: Contribution
+      description: Are you willing to contribute to this feature?
+      options:
+        - label: I'm willing to submit a PR for this feature
+        - label: I can help with testing
+        - label: I can help with documentation