Missing docs for Div, Rem, Shl and Shr (they show Mul instead.)

[Achtuur]

The docs for Div, Rem, Shl and Shr are showing the docs for Mul instead. The culprit is most likely the following:

derive_more/impl/src/lib.rs

Lines 221 to 225 in 3216eaf

	create_derive!("mul", mul_like, Mul, mul_derive, mul);
	create_derive!("mul", mul_like, Div, div_derive, div);
	create_derive!("mul", mul_like, Rem, rem_derive, rem);
	create_derive!("mul", mul_like, Shr, shr_derive, shr);
	create_derive!("mul", mul_like, Shl, shl_derive, shl);

It seems that there are no doc/(div|rem|shl|shr).md, so only changing the $feature string here would not work.