Docs: simple docstring for `write(filename::AbstractString, x)` (#49835)
* Docs: simple docstring for `write(filename::AbstractString, x)`
* use `content` instead of `x`
* Update base/io.jl
Co-authored-by: Jameson Nash <vtjnash@gmail.com>
* Update base/io.jl
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Co-authored-by: Jameson Nash <vtjnash@gmail.com>