references to all the other miriad siblings

[teuben]

the readme file should list a URL reference to the other miriad siblings:

1. CARMA miriad (Peter Teuben) - yes, the original one (Peter Williams maintains a parallel git repo)
2. SMA miriad (Jun-Hui Zhao) - derived from CARMA
3. ATNF miriad (Mark Wieringa) - long time split from CARMA
4. WSRT miriad (Thijs vd Hulst) - derived from ATNF

hopefully there are no more