Add contributor documentation

Author: jlb6740

CONTRIBUTING.md

@@ -0,0 +1,12 @@
+# Contributing to WasmScore
+
+Wasmscore is a [Bytecode Alliance] project. It follows the Bytecode
+Alliance's [Code of Conduct] and [Organizational Code of Conduct].
+
+For more information about contributing to this project you can consult the
+[online documentation] which should cover all sorts of topics.
+
+[Bytecode Alliance]: https://bytecodealliance.org/
+[Code of Conduct]: CODE_OF_CONDUCT.md
+[Organizational Code of Conduct]: ORG_CODE_OF_CONDUCT.md
+[online documentation]: https://bytecodealliance.github.io/wasmtime/contributing.html