f06178a218b66cfd0462db5ea71093cb6b2cc88e doc: dseries slides touch ups

================================ DYNARE MAKE CHECK MATLAB RESULTS ================================ | TOTAL: 444 | PASS: 438 | FAIL: 4 | XFAIL: 2 | XPASS: 0 | LIST OF FAILED TESTS: | * ep/rbc.mod | * ep/rbc2.mod | * ep/rbcii.mod | * ep/linearmodel.mod

================================ DYNARE MAKE CHECK OCTAVE RESULTS ================================ | TOTAL: 442 | PASS: 436 | FAIL: 4 | XFAIL: 2 | XPASS: 0 | LIST OF FAILED TESTS: | * ep/rbc.mod | * ep/rbc2.mod | * ep/rbcii.mod | * ep/linearmodel.mod

A full log can be found on karaba in '/tmp/dynare-master-check-gp4dAgRxnT.log'.