Add issue and pull request templates

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -0,0 +1,77 @@
+# SPDX-FileCopyrightText: 2023 Shun Sakai
+#
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+
+name: 🐞 Bug report
+description: Create a report to help us improve
+labels: ["bug"]
+
+body:
+  - type: checkboxes
+    attributes:
+      label: Checklist
+      options:
+        - label: I have searched the existing issues
+          required: true
+
+  - 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: Steps to reproduce the behavior.
+    validations:
+      required: false
+
+  - type: textarea
+    attributes:
+      label: Expected behavior
+      description: A clear and concise description of what you expected to happen.
+    validations:
+      required: true
+
+  - type: input
+    attributes:
+      label: sysexits-rs version
+      description: Can be found in `Cargo.toml` of your project.
+      placeholder: 0.1.0
+    validations:
+      required: true
+
+  - type: input
+    attributes:
+      label: Rust version
+      description: Output of `rustc -V`.
+      placeholder: 1.56.0
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Environment
+      description: Tell us where on the platform it happens.
+      placeholder: |
+        - OS: Debian 12
+        - arch: x86_64
+    validations:
+      required: false
+
+  - type: textarea
+    attributes:
+      label: Additional context
+      description: Add any other context about the problem here.
+    validations:
+      required: false
+
+  - type: checkboxes
+    attributes:
+      label: Code of Conduct
+      description: By submitting this issue, you agree to follow our [Code of Conduct](../../CODE_OF_CONDUCT.md)
+      options:
+        - label: I agree to follow this project's Code of Conduct
+          required: true

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -0,0 +1,37 @@
+# SPDX-FileCopyrightText: 2023 Shun Sakai
+#
+# SPDX-License-Identifier: Apache-2.0 OR MIT
+
+name: 💡 Feature request
+description: Suggest an idea for this project
+labels: ["enhancement"]
+
+body:
+  - type: checkboxes
+    attributes:
+      label: Checklist
+      options:
+        - label: I have searched the existing issues
+          required: true
+
+  - type: textarea
+    attributes:
+      label: Summary
+      description: A clear and concise description of what the suggestion is.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Additional context
+      description: Add any other context about the feature request here.
+    validations:
+      required: false
+
+  - type: checkboxes
+    attributes:
+      label: Code of Conduct
+      description: By submitting this issue, you agree to follow our [Code of Conduct](../../CODE_OF_CONDUCT.md)
+      options:
+        - label: I agree to follow this project's Code of Conduct
+          required: true

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md

@@ -0,0 +1,22 @@
+## Description
+
+<!-- Describe your changes in detail. -->
+
+<!--
+If it resolves an open issue, link to the issue here, otherwise remove this
+line.
+-->
+
+Closes #
+
+## Additional context
+
+<!-- If you have any other context, describe them here. -->
+
+## Checklist
+
+- [ ] I have read the [Contribution Guide].
+- [ ] I agree to follow the [Code of Conduct].
+
+[Contribution Guide]: ../../CONTRIBUTING.adoc
+[Code of Conduct]: ../../CODE_OF_CONDUCT.md

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md.license

@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2023 Shun Sakai
+
+SPDX-License-Identifier: Apache-2.0 OR MIT

CONTRIBUTING.adoc

@@ -16,6 +16,20 @@ The branching model of this project is based on the {git-flow-url}[git-flow].
 
 Please see the {commit-messages-guide-url}[Commit messages guide].
 
+== Submitting a pull request
+
+. Create a working branch from the `develop` branch. The branch name should be
+  something other than `develop` or `master`.
+. Create your patch. If your change is a feature or a bugfix, please add a test
+  case if possible. Note that the change must pass the CI.
+. Please update the copyright information if possible. This project is
+  compliant with version 3.0 of the
+  https://reuse.software/spec/[_REUSE Specification_].
+  https://github.com/fsfe/reuse-tool[`reuse`] is useful for updating the
+  copyright information.
+. Please update the link:CHANGELOG.adoc[Changelog] if possible.
+. Please read and agree to follow the link:CODE_OF_CONDUCT.md[Code of Conduct].
+
 == Development
 
 === Useful development tools