###### Motivation for this change
With space between two options, multiple options just don't work
Looks like xkbOptions then used for generation of xorg.conf.d/00-keyboard.conf.
kbd's man says XkbOptions must be comma-separated without spaces.
https://linux.die.net/man/4/kbd

###### Things done

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- Built on platform(s)
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- [ ] Tested via one or more NixOS test(s) if existing and applicable for the change (look inside [nixos/tests](https://github.com/NixOS/nixpkgs/blob/master/nixos/tests))
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- [ ] Fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).

###### Notify maintainers

cc @

Fix example for xkbOptions

Fix example for xkbOptions