update contributing file re. licensing changes and prev. contributions (

#892)

CONTRIBUTING.md

@@ -5,6 +5,10 @@ practices and development tools we use.
 
 When you contribute code, you affirm that the contribution is your original work and that you license the work to the project under the project's license. Whether or not you state this explicitly, by submitting any copyrighted material via pull request, email, or other means you agree to license the material under the project's license and warrant that you have the legal authority to do so.
 
+# Alibi Detect Licensing
+
+As of 22 January 2024, contributions to Seldon's open source and source available projects are governed by Seldon's Contributor License Agreement ("CLA").  For certain contributions previously contributed to Seldon's open source projects under the Apache 2.0 license, the individual contributions will remain open source under the Apache 2.0 license (see [here](https://github.com/SeldonIO/alibi-detect/blob/v0.11.4/LICENSE)), but Seldon may include such contribution as part of a larger project that constitutes a derivative work of the project and is licensed as a whole under the Business Source License 1.1.  A list of individual contributions that are subject to the Apache 2.0 license are listed [here](oss_commits.md).
+
 ## Getting started
 The easiest way to get started is to install all the development dependencies
 in a separate virtual environment:

oss_commits.md

@@ -0,0 +1,5 @@
+# External contributor summary
+
+The following are external contributions were made before the licensing changes applied to Seldon's Alibi Detect in January 2024. These contributions previously contributed to Alibi Detect under the Apache 2.0 license, however Seldon may include such contributions as part of a larger project that constitutes a derivative work of the project and is licensed as a whole under the Business Source License 1.1.
+
+[d4014df](https://github.com/SeldonIO/alibi-detect/commit/d4014df), [5642b02](https://github.com/SeldonIO/alibi-detect/commit/5642b02), [d188e02](https://github.com/SeldonIO/alibi-detect/commit/d188e02), [fa8f8b6](https://github.com/SeldonIO/alibi-detect/commit/fa8f8b6), [6b8b1c8](https://github.com/SeldonIO/alibi-detect/commit/6b8b1c8), [d5cf67b](https://github.com/SeldonIO/alibi-detect/commit/d5cf67b), [46576a3](https://github.com/SeldonIO/alibi-detect/commit/46576a3), [d38b327](https://github.com/SeldonIO/alibi-detect/commit/d38b327), [31dc64d](https://github.com/SeldonIO/alibi-detect/commit/31dc64d), [573ef3b](https://github.com/SeldonIO/alibi-detect/commit/573ef3b), [7497cdc](https://github.com/SeldonIO/alibi-detect/commit/7497cdc), [1191b72](https://github.com/SeldonIO/alibi-detect/commit/1191b72), [08267bd](https://github.com/SeldonIO/alibi-detect/commit/08267bd), [31fb0b8](https://github.com/SeldonIO/alibi-detect/commit/31fb0b8)