Add docstrings to exp10 functions

src/math/exp10.rs

@@ -6,6 +6,7 @@ const P10: &[f64] = &[
     1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11, 1e12, 1e13, 1e14, 1e15,
 ];
 
+/// Calculates 10 raised to the power of `x` (f64).
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn exp10(x: f64) -> f64 {
     let (mut y, n) = modf(x);

src/math/exp10f.rs

@@ -5,6 +5,7 @@ const LN10_F64: f64 = 3.32192809488736234787031942948939;
 const P10: &[f32] =
     &[1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1, 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7];
 
+    /// Calculates 10 raised to the power of `x` (f32).
 #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
 pub fn exp10f(x: f32) -> f32 {
     let (mut y, n) = modff(x);