Added PROFESSIONAL-SUPPORT.md list of service providers

RaptorJIT users need to know that there is professional support
available if and when they need it. This is to reduce the risks
associated with starting new projects (e.g. missing deadlines due to
learning curve) and to reduce the costs of maintaining these
applications (e.g. having in-house JIT internals gurus who need to be
hired/trained/retained/replaced/etc over time.)

PROFESSIONAL-SUPPORT.md

@@ -0,0 +1,10 @@
+Professional support is available to help you use RaptorJIT
+successfully. You can contact the parties listed below if you need
+help to design your application; to understand the compiler and the
+tools; to fix bugs and optimize code; to maintain a port to a new
+platform; etc.
+
+Links in alphabetical order with one-sentence summaries:
+
+- [Snabb Solutions](https://snabb.solutions/) offers consulting and standard support agreements for RaptorJIT and related projects.
+