Update README

Author: auriocus

README.md

@@ -8,3 +8,29 @@ and should eventually be pushed upstream to tclconfig/sampleextension located he
 * https://core.tcl-lang.org/tclconfig
 
 I don't plan long-term maintenance once the porting is done (started in July 2021)
+
+This example demonstrates a simple animal class (see `generic/sample.hpp` and `generic/sample.cpp`). 
+Below is a transcript from using the library:
+
+	(sampleextension-cpp) 49 % load ./libsample0.5.dylib
+	(sampleextension-cpp) 50 % ::sample::Animal chris dog 5
+	_f0c9461fdd7f0000_p_Animal
+	(sampleextension-cpp) 51 % chris describe
+	I am a dog and I am 5 years old
+	(sampleextension-cpp) 52 % chris birthday
+	6
+	(sampleextension-cpp) 53 % chris birthday
+	7
+	(sampleextension-cpp) 53 % chris describe
+	I am a dog and I am 7 years old
+	(sampleextension-cpp) 54 % chris cget -type
+	dog
+	(sampleextension-cpp) 55 % chris cget -age
+	7
+	(sampleextension-cpp) 56 % chris configure -type cat
+	(sampleextension-cpp) 57 % chris describe
+	I am a cat and I am 7 years old
+	(sampleextension-cpp) 58 % chris -delete
+	(sampleextension-cpp) 59 % ::sample::Animal chris dog -3
+	RuntimeError Age cannot be negative!
+	(sampleextension-cpp) 60 %