Use idiomatic/canonical option type annotations in Result module

Result.toOption has return type Option<'T>. The idiomatic/canonical notation is 'T option. The use of Option<'T> here means that Option<'T> shows up in code/line lens and tooltips all over my codebase when using this function, whereas I would prefer 'T option.

I haven’t checked, but I am guessing that this could apply to other functions in the Result module, too.

For completeness, note that the same kind of issue would also apply to functions typed with List<'T> instead of 'T list, and other similar types. (I haven’t checked or encountered any, though.)

[cmeeren]

So I would only be changing to postfix lowercase notation in signature files for these?

• option
• voption
• list
• ref

Apart from [], these are the only ones listed in the formatting guidelines, so I guess the list is complete.

[edgarfgp]

Regarding array changes. The remaining work is tracked here https://github.com/dotnet/fsharp/issues/14329.

• Update FSharp.Core API reference
• Update docs