docs: fix comments in normal distribution CDF

Author: manvith2003

lib/node_modules/@stdlib/stats/base/dists/normal/cdf/lib/native.js

@@ -32,7 +32,7 @@ var addon = require( './../src/addon.node' );
 * @param {number} x - input value
 * @param {number} mu - mean
 * @param {number} sigma - standard deviation
-* @returns {Probability} evaluated CDF
+* @returns {Probability} evaluated cumulative distribution function
 *
 * @example
 * var y = cdf( 2.0, 0.0, 1.0 );

lib/node_modules/@stdlib/stats/base/dists/normal/cdf/src/main.c

@@ -26,9 +26,9 @@
 * with mean `mu` and standard deviation `sigma` at a value `x`.
 *
 * @param x input value
-* @param mu mean of the distribution
-* @param sigma standard deviation of the distribution
-* @return evaluated CDF
+* @param mu mean 
+* @param sigma standard deviation 
+* @return evaluated cumulative distribution function
 *
 * @example
 * double y = stdlib_base_arcsine_cdf( 2.0, 0.0, 1.0 );