mention axes in docs instead of size (#26233)

base/abstractarray.jl

@@ -29,6 +29,9 @@ Return a tuple containing the dimensions of `A`. Optionally you can specify the
 dimension(s) you want the length of, and get the length of that dimension, or a tuple of the
 lengths of dimensions you asked for.
 
+Note that `size` may not be defined for arrays with non-standard indices, in which case [`axes`](@ref)
+may be useful. See the manual chapter on [arrays with custom indices](@ref man-custom-indices).
+
 # Examples
 ```jldoctest
 julia> A = fill(1, (2,3,4));
@@ -49,6 +52,8 @@ size(x, d1::Integer, d2::Integer, dx::Vararg{Integer, N}) where {N} =
 
 Return the valid range of indices for array `A` along dimension `d`.
 
+See also [`size`](@ref), and the manual chapter on [arrays with custom indices](@ref man-custom-indices).
+
 # Examples
 ```jldoctest
 julia> A = fill(1, (5,6,7));

base/generator.jl

@@ -64,7 +64,7 @@ Given the type of an iterator, return one of the following values:
 * `SizeUnknown()` if the length (number of elements) cannot be determined in advance.
 * `HasLength()` if there is a fixed, finite length.
 * `HasShape{N}()` if there is a known length plus a notion of multidimensional shape (as for an array).
-   In this case `N` should give the number of dimensions, and the [`size`](@ref) function is valid
+   In this case `N` should give the number of dimensions, and the [`axes`](@ref) function is valid
    for the iterator.
 * `IsInfinite()` if the iterator yields values forever.
 

doc/src/devdocs/offset-arrays.md

@@ -1,4 +1,4 @@
-# Arrays with custom indices
+# [Arrays with custom indices](@id man-custom-indices)
 
 Julia 0.5 adds experimental support for arrays with arbitrary indices. Conventionally, Julia's
 arrays are indexed starting at 1, whereas some other languages start numbering at 0, and yet others