added TwoJoint example

examples/TwoJoint/README.md

@@ -0,0 +1,13 @@
+
+* Build as usual
+* Run the executable and log the stdout output (for about 6 seconds, then hit escape to stop)
+
+```
+> App_TwoJoint > output.txt
+```
+
+* open `output.txt` and copy the numeric output to the clipboard
+* open MATLAB (R2017A+), and type (without hitting enter) `> b3Output500 = [`
+* hit ctrl+v etc. to paste long output
+* type `];` and hit enter (takes a few seconds)
+* run the script `compareBulletMATLAB`