Fix inequality in docs for div_euclid

This commit fixes the statement of the inequality that the Euclidean
remainder satisfies. (The remainder is guaranteed to be less than
abs(rhs), not rhs.) It also rewords the documentation to make it a
little easier to read.

Author: jturner314

library/core/src/num/int_macros.rs

@@ -1589,11 +1589,11 @@ macro_rules! int_impl {
 
         /// Calculates the quotient of Euclidean division of `self` by `rhs`.
         ///
-        /// This computes the integer `n` such that `self = n * rhs + self.rem_euclid(rhs)`,
-        /// with `0 <= self.rem_euclid(rhs) < rhs`.
+        /// This computes the integer `q` such that `self = q * rhs + r`, with
+        /// `r = self.rem_euclid(rhs)` and `0 <= r < abs(rhs)`.
         ///
-        /// In other words, the result is `self / rhs` rounded to the integer `n`
-        /// such that `self >= n * rhs`.
+        /// In other words, the result is `self / rhs` rounded to the integer `q`
+        /// such that `self >= q * rhs`.
         /// If `self > 0`, this is equal to round towards zero (the default in Rust);
         /// if `self < 0`, this is equal to round towards +/- infinity.
         ///