Update spelling and contributing

Author: Gijsreyn

.github/actions/spelling/expect/software.txt

@@ -0,0 +1 @@
+csharpier

CONTRIBUTING.md

@@ -1,3 +1,42 @@
 # Contributing
 
-Will be written soon.
+Thanks for your interest in contributing to `bicep-local-docgen`! Here are a few general
+guidelines on contributing andreporting bugs that we ask you to review. Following these
+guidelines helps to communicate that you respect the time of the contributors managing
+and developing this open source project.
+
+## Reporting Issues
+
+Before reporting a new issue, please ensure that the issue was not already reported or
+fixed by searching through our [issues list][00].
+
+When creating a new issue, please be sure to include a **title and clear description**,
+as much relevant information as possible, and, if possible, a test case.
+
+## Sending Pull Requests
+
+Before sending a new pull request, take a look at existing pull requests and issues to
+see if the proposed change or fix has been discussed in the past, or if the change was
+already implemented but not yet released.
+
+We expect new pull requests to include tests for any affected behavior, and, as we
+follow semantic versioning, we may reserve breaking changes until the next major version
+release.
+
+## Other Ways to Contribute
+
+We welcome anyone that wants to contribute to `bicep-local-docgen` to triage and reply to
+open issues to help troubleshoot and fix existing bugs. Here is what you can do:
+
+- Help ensure that existing issues follows the recommendations from the _[Reporting Issues][01]_
+  section, providing feedback to the issue's author on what might be missing.
+  instructions and code samples.
+- Review existing pull requests, and testing patches against real existing applications that use
+  `bicep-local-docgen`.
+- Write a test, or add a missing test case to an existing test.
+
+Thanks again for your interest on contributing to `bicep-local-docgen`!
+
+<!-- Link reference definitions -->
+[00]: https://github.com/Gijsreyn/bicep-local-docgen/issues
+[01]: #reporting-issues