Add TONE3000 support note in README.md (#224)

Author: sdatkinson

README.md

@@ -12,3 +12,12 @@ You should be able to run it locally to test if you'd like.
 
 ## Sharp edges
 This library uses [Eigen](http://eigen.tuxfamily.org) to do the linear algebra routines that its neural networks require. Since these models hold their parameters as eigen object members, there is a risk with certain compilers and compiler optimizations that their memory is not aligned properly. This can be worked around by providing two preprocessor macros: `EIGEN_MAX_ALIGN_BYTES 0` and `EIGEN_DONT_VECTORIZE`, though this will probably harm performance. See [Structs Having Eigen Members](http://eigen.tuxfamily.org/dox-3.2/group__TopicStructHavingEigenMembers.html) for more information. This is being tracked as [Issue 67](https://github.com/sdatkinson/NeuralAmpModelerCore/issues/67).
+
+## Sponsors
+
+<div align="center">
+  <img src="media/tone3000-logo.svg" alt="Tone3000 logo">
+</div>
+
+Development of version 0.4.0 of this library has been generously supported by [TONE3000](https://tone3000.com). 
+**Thank you!**