Add an example of using GENERATE(table())

There are some examples on issue #850 of using this feature, but they
are not easily found from the documentation. Adding them here as an
example makes them more findable and ensures they keep working if the
API changes.

examples/CMakeLists.txt

@@ -32,6 +32,7 @@ set( SOURCES_IDIOMATIC_EXAMPLES
     210-Evt-EventListeners.cpp
     300-Gen-OwnGenerator.cpp
     301-Gen-MapTypeConversion.cpp
+    302-Gen-Table.cpp
     310-Gen-VariablesInGenerators.cpp
     311-Gen-CustomCapture.cpp
 )