feat(config): add partial types for each config option

[NStefan002]

As mentioned in #427, I added all of the partial config definitions to config/types_partial. I didn't create a Partial pair for very few of them (e.g. blink.cmp.KeymapConfig) because all of their fields are already optional.

If you want me to change something (split this into multiple files / remove fields' comments / etc. ), let me know.

Edit: these are the types after be3e9cf

[folke]

fyi: a simple way to make a partial of a type is by doing:

---@class foo.partial: foo,{}

or just do:

---@param opts? blink.Opts|{}
function foo(opts)end

[NStefan002]

@folke Thank you! I had no idea you could do it like that, I'll update it.

[NStefan002]

Ok, I realised some problems now, I'll fix it shortly...

[Saghen]

Thank you!