Update readme and contributing guide to mention the commerical license

Author: ptheywood

CONTRIBUTING.md

@@ -78,11 +78,13 @@ This ensure that users on both Linux and Windows can continue to build FLAME GPU
 
 ## License
 
-FLAME GPU is distributed under [AGPL-3.0-only Licence](https://github.com/FLAMEGPU/FLAMEGPU2/blob/master/LICENSE.md).
+- [AGPL-3.0-only license](https://github.com/FLAMEGPU/FLAMEGPU2/blob/master/LICENSE.md) for open source usage
+- A commercial licenses for cases where the use of the open source AGPL-licensed version is not possible or desirable. Please see [flamegpu.com/download/licence/](https://flamegpu.com/download/licence/) for more information.
 
 ### Contributor License Agreement (CLA)
 
-Before we can accept your pull request, you need to sign our CLA. Our CLA assistant should check and prompt you to sign the CLA when you create your pull request.
+Before we can accept your pull request, you need to sign our [CLA](https://flamegpu.com/download/cla/).
+Our CLA assistant should check and prompt you to sign the CLA when you create your pull request.
 
 ## Creating a Release
 

README.md

@@ -364,7 +364,10 @@ Alternatively, [CITATION.cff](https://github.com/FLAMEGPU/FLAMEGPU2/blob/master/
 
 ## License
 
-FLAME GPU is distributed under [AGPL-3.0-only Licence](https://github.com/FLAMEGPU/FLAMEGPU2/blob/master/LICENSE.md).
+FLAME GPU is available under two licenses:
+
+- [AGPL-3.0-only license](https://github.com/FLAMEGPU/FLAMEGPU2/blob/master/LICENSE.md) for open source usage
+- A commercial licenses for cases where the use of the open source AGPL-licensed version is not possible or desirable. Please see [flamegpu.com/download/licence/](https://flamegpu.com/download/licence/) for more information.
 
 ## Known issues