Add contributing instructions

CONTRIBUTING.md

@@ -0,0 +1,19 @@
+# Contributing to Timescale Examples
+
+We appreciate any help the community can provide to make examples of using TimescaleDB better!
+
+You can help in different ways:
+
+* Open an [issue](https://github.com/timescale/examples/issues) with a
+  bug report, build issue, feature request, suggestion, etc.
+
+* Fork this repository and submit a pull request
+
+For any particular improvement you want to make, it can be beneficial to
+begin discussion on the GitHub issues page.
+
+Before we accept any code contributions, Timescale contributors need to sign
+the [Contributor License
+Agreement](https://cla-assistant.io/timescale/examples) (CLA). By signing a
+CLA, we can ensure that the community is free and confident in its ability to
+use your contributions.