> Something like this?
>
> --- i/nt/README.W32
> +++ w/nt/README.W32
> @@ -94,6 +94,12 @@ See the end of the file for license conditions.
>    (non-windowed) mode of operation is most useful if you have a telnet
>    server on your machine, allowing you to run Emacs remotely.
>
> +* Pinning Emacs to the taskbar (Windows 7 and higher)
> +
> +  After starting Emacs the first time, pin it to the taskbar, then
> +  edit the properties (via shift-right-click) so that the executable
> +  path to points to runemacs.exe instead of emacs.exe.
> +
>  * EXE files included
>
>    Emacs comes with the following executable files in the bin directory.

Yes, though the emacs-25 branch already has something like that in nt/README.W32

It's talking about a desktop shortcut and not the taskbar, but it is the same idea. Perhaps change it to "If you create a desktop shortcut for invoking Emacs, or pin Emacs to the taskbar, modify the shortcut so it points to this executable, not to emacs.exe". Or something like that.