ref.rdoc in gsl-2.1.0

- old
+ new

@@ -82,9 +82,10 @@
 #    1. quartic
 #    1. jacobi (see examples/jacobi/*.rb)
 #    1. {NDLINEAR: multi-linear, multi-parameter least squares fitting}[link:rdoc/ndlinear_rdoc.html]
 #    1. {ALF: associated Legendre polynomials}[link:rdoc/alf_rdoc.html]
 # 1. {NArray compatibilities}[link:rdoc/narray_rdoc.html]
+# 1. {NMatrix compatibilities}[link:rdoc/nmatrix_rdoc.html]
 # 1. {Changes since Ruby/GSL 1.10.3}[link:rdoc/changes_rdoc.html]
 # 1. {GNU Free Documentation Licence}[https://gnu.org/software/gsl/manual/html_node/GNU-Free-Documentation-License.html]
 #
 # {next}[link:rdoc/intro_rdoc.html]
 #