Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,9 +1,33 @@
-Please always create unit test for your contributions, and make sure they are passing.
+# Contributing
 
-Tests are created using jasmine
+When contributing to this repository, please explain your changes or additions in an issue or in the pull request. 
 
-You can run unit tests by:
-* `npm test` or
-* `make test`
+When developing, please:
 
-See `Makefile` for additional test suites
+* Comply with Standard JS. This is tested when you commit to natural.
+* Prevent code duplication. Use jscpd to test this. This is tested when you commit to natural.
+* Write unit tests for jasmine. Make sure your unit tests pass.
+* For compatibility with browsers, do not use the file system fs. If you need to read files, use JSON and require.
+* Write documentation and commit this to the gh-pages branch.
+* The current configuration of the unit tests requires the following environment variable to be set:
+```
+    export NODE_PATH=.
+```
+
+# CD/CD pipeline
+The repository uses Github Actions for testing and publishing.
+
+Currently, there three workflows:
+
+* Node CI: tests natural on the four most recent releases of Nodejs. Code coverage is analysed with Istanbul. Results are forwarded to Coveralls. In the README a badge shows the coverage.
+* Nodejs package: The natural package is automatically published to NPM when a release is created (tagged).
+* Lint Code Base: the repository is linted using the Github super linter which includes jslint and jscpd.
+* CodeQL for detecting security vulnerabilities.
+Github workflows can be found in the folder ./.github/workflows.
+
+# Versioning
+We apply semantic versioning. Given natural’s version number MAJOR.MINOR.PATCH, increment the:
+
+* MAJOR version when you make incompatible API changes,
+* MINOR version when you add functionality in a backwards compatible manner, and
+* PATCH version when you make backwards compatible bug fixes.