docs(matrices): update hilbert and inv hilbert doc

Author: AnzhiZhang

Diff for: src/matrices/hilbert.jl

@@ -5,6 +5,8 @@ The Hilbert matrix has `(i,j)` element `1/(i+j-1)`. It is
 notorious for being ill conditioned. It is symmetric
 positive definite and totally positive.
 
+See also [`InverseHilbert`](@ref).
+
 # Input Options
 - dim: the dimension of the matrix.
 - row\\_dim, col\\_dim: the row and column dimensions.

Diff for: src/matrices/inversehilbert.jl

@@ -2,6 +2,8 @@
 Inverse of the Hilbert Matrix
 =============================
 
+See also [`Hilbert`](@ref).
+
 # Input Options
 - dim: the dimension of the matrix.