updated doctests

Author: torfjelde

src/varname.jl

@@ -17,13 +17,13 @@ indexing expression through the [`@varname`](@ref) convenience macro.
 
 ```jldoctest
 julia> vn = VarName{:x}(((Colon(), 1), (2,)))
-x[Colon(),1][2]
+x[:,1][2]
 
 julia> vn.indexing
 ((Colon(), 1), (2,))
 
 julia> @varname x[:, 1][1+1]
-x[Colon(),1][2]
+x[:,1][2]
 ```
 """
 struct VarName{sym, T<:Tuple}