Create CONTRIBUTING.md, prepare issue and pull request templates

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,28 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+assignees: ''
+
+---
+
+**What version of Zserio and what language are you using?**
+Zserio: 2.12.0
+Language: C++/Java/Python
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+* Schema (minimum working example)
+* Zserio command line options (e.g. -withTypeInfoCode)
+* Sample code (*.cpp / *.java / *.py)
+* Error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Additional context:**
+Provide relevant information about your OS, used Java version, Python version and/or C++ compiler version.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Question
+    url: https://github.com/ndsev/zserio/discussions/new?category=q-a
+    about: Ask questions here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: enhancement
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is.
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/pull_request_template.md

@@ -0,0 +1,11 @@
+**Please check [contribution guide](https://github.com/ndsev/zserio/CONTRIBUTING.md) first.**
+
+# Description
+
+Include a summary of the change and which issue is fixed.
+
+# Type of Change
+
+* [ ] Bug fix
+* [ ] New feature
+* [ ] Documentation enhancement

CONTRIBUTING.md

@@ -0,0 +1,76 @@
+# Contributing to Zserio
+
+The following summarizes the process for contributing changes to the Zserio project.
+
+## Where to start
+
+* [Zserio Build Instructions](doc/ZserioBuildInstructions.md).
+
+## General rules for any code contribution
+
+* Consider to open a [discussion](https://github.com/ndsev/zserio/discussions/new/choose)
+  or create an [issue](https://github.com/ndsev/zserio/issues/new/choose).
+
+* Open a new GitHub pull request.
+
+* Follow our coding style.
+
+  * For all C++ and Java code we use **clang-format** to check that the code follow the defined
+    [coding style](.clang-format).
+
+    > Note that you have to run `clang-format` on your own, our pipeline only checks that the code follows
+      the rules.
+
+  * Python code is not yet automatically checked, please try use the same coding style as is used in our
+    [Python runtime library](https://github.com/ndsev/zserio/tree/master/compiler/extensions/python/runtime/src/zserio)
+    (in general we follow the [PEP-8](https://www.python.org/dev/peps/pep-0008/)).
+
+* Ensure that all GitHub [workflows](https://github.com/ndsev/zserio/actions) are passing.
+
+* Wait for the review by [@Mi-La](https://github.com/Mi-La) or [@mikir](https://github.com/mikir).
+
+> Please try to address only a single problem in you pull request.
+
+## Did you find a bug?
+
+* Ensure that the bug was not already reported in some [issue](https://github.com/ndsev/zserio/issues).
+
+* If there is no open issue addressing the problem,
+  [open a new one](https://github.com/ndsev/zserio/issues/new?assignees=&labels=bug&projects=&template=bug_report.md&title=).
+
+* Follow [General rules for any code contribution](#general-rules-for-any-code-contribution).
+
+## Do you want to propose a performance optimization?
+
+* Consider to open a [discussion](https://github.com/ndsev/zserio/discussions/new/choose)
+  or create an [issue](https://github.com/ndsev/zserio/issues/new/choose).
+
+* Run our [benchmarks](https://github.com/ndsev/zserio/tree/master/benchmarks) and provide comparison with the latest zserio release
+  in your Pull Request.
+
+* Feel free to provide any other measurements.
+
+* Follow [General rules for any code contribution](#general-rules-for-any-code-contribution).
+
+## Do you want to propose a new feature?
+
+* Consider to open a [discussion](https://github.com/ndsev/zserio/discussions/new?category=ideas) or create an
+  [issue](https://github.com/ndsev/zserio/issues/new?assignees=&labels=&projects=&template=feature_request.md&title=).
+
+* The proposed changes must not break
+  [backward compatibility](doc/ZserioCompatibilityGuide.md#schema-language-compatibility).
+
+## Do you intend to write a new generator?
+
+* Consider to open a [discussion](https://github.com/ndsev/zserio/discussions/new?category=ideas) or create an
+  [issue](https://github.com/ndsev/zserio/issues/new?assignees=&labels=&projects=&template=feature_request.md&title=).
+
+* In case you want to implement a new generator (i.e. zserio extension), you can start with
+  [Zserio Extension Sample](https://github.com/ndsev/zserio-extension-sample)
+  and keep it as an external extension. We will be happy to add a link to your extension in our [README.md](README.md)!
+
+## License
+
+We do not require any formal copyright assignment or contributor license agreement (CLA).
+Any contributions intentionally sent upstream are presumed to be offered under terms of BSD 3-Clause License.
+See [LICENSE](https://github.com/ndsev/zserio/LICENSE) for details.

README.md

@@ -182,3 +182,10 @@ by Zserio. However, Zserio provides sample implementations of several Pub/Sub ba
 Note that Zserio doesn't provide any Pub/Sub server. There are various implementations of servers
 (e.g. [mosquitto](https://github.com/eclipse/mosquitto)) and it's the responsibility of the user's Pub/Sub
 client implementation to communicate with the appropriate server.
+
+## Contributions
+
+Contributions are very welcome but we encourage to open a
+[discussion](https://github.com/ndsev/zserio/discussions/new/choose) or
+an [issue](https://github.com/ndsev/zserio/issues/new) first to agree on a solution or to avoid useless work
+in case we are already solving a similar problem. Please see [Contribution Guide](CONTRIBUTING.md).