docs: add missing tag and fix description

PR-URL: #12821
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: Planeshifter

lib/node_modules/@stdlib/number/float16/base/from-word/lib/native.js

@@ -28,6 +28,7 @@ var addon = require( './../src/addon.node' );
 /**
 * Creates a half-precision floating-point number from an unsigned integer corresponding to an IEEE 754 binary representation.
 *
+* @private
 * @param {uinteger16} word - unsigned integer
 * @returns {number} half-precision floating-point number
 *

lib/node_modules/@stdlib/number/float16/base/signbit/lib/native.js

@@ -31,7 +31,7 @@ var addon = require( './../src/addon.node' );
 *
 * @private
 * @param {number} x - input value
-* @returns {boolean} - boolean indicating if sign bit is on or off
+* @returns {boolean} boolean indicating if sign bit is on or off
 *
 * @example
 * var toFloat16 = require( '@stdlib/number/float64/base/to-float16' );