Docs: simple docstring for write(filename::AbstractString, x)

[fonsp]

Point 2 of #43428.

I also changed "the canonical binary representation of a value" to just say "x".
It felt like a very complex way of saying that it does what you think it does. 🙂 I think it's good to document it like this for the write(io::IO, x) method, but as I expressed in #43428, I think we should document the write(filename::String, content) method in a more beginner-friendly way.

[Seelengrab]

I also changed "the canonical binary representation of a value" to just say "x".

The distinction is important though - writing the binary representation of 1.0 to a file is very different from taking 1.0 and writing that to a file (i.e., what print would do). You can't open the resulting file with a text editor and see 1.0 there. That write doesn't print is quite literally the defining distinction of the two.

[fonsp]

I see! Is it possible to link to the other method's documentation? I feel like it is important to keep this method's documentation accessible to people without a CS/math background.

[Seelengrab]

For linking other functions, it's usually done like this:

See also: [`print`](@ref).

which will link to the documentation of print.

I feel like it is important to keep this method's documentation accessible to people without a CS/math background.

I'm not sure this is possible - we have to stop explaining at some point, otherwise docstrings get too long and miss their actual purpose, documenting what a given method does. For write, I think mentioning that this writes the binary representation is the most accurate it can be, without being overly off-topic. It'd be weird to start explaining in a docstring that there's a difference between displaying a value and how its represented internally. That's more the job of a manual or tutorial than that of a docstring.