added qbmm stuff to doc

Author: sbryngelson

doc/basics_of_qbmm.md

@@ -0,0 +1,15 @@
+'qbmm'               : 'T',
+    * Turns on QBMM. It uses CHyQMOM.
+'nnode'              : 4,
+    * Number of quadrature points. 
+    * Currently 4 is the only option.
+'dist_type'          : 2,
+    * 1 = Binormal distribution
+    * 2 = Lognormal in R, Normal in V (Rdot)
+    * Both of these use mean in R = 1, mean in V = 0
+'sigR'               : 0.1,
+    * Standard deviation of distribution in R
+'sigV'               : 0.1,
+    * Standard deviation of distribution in V (Rdot)
+'rhoRV'              : 0.0,
+    * Initial covariance between R and V directions (usually 0)