Improve jsdoc for is-object

lib/is-object.js

@@ -1,12 +1,19 @@
 "use strict";
 
-// Returns true when the value is a regular Object and not a specialized Object
-//
-// This helps speeding up deepEqual cyclic checks
-// The premise is that only Objects are stored in the visited array.
-// So if this function returns false, we don't have to do the
-// expensive operation of searching for the value in the the array of already
-// visited objects
+/**
+ * Returns `true` when the value is a regular Object and not a specialized Object
+ *
+ * This helps speed up deepEqual cyclic checks
+ *
+ * The premise is that only Objects are stored in the visited array.
+ * So if this function returns false, we don't have to do the
+ * expensive operation of searching for the value in the the array of already
+ * visited objects
+ *
+ * @private
+ * @param  {object}   value The object to examine
+ * @returns {boolean}       `true` when the object is a non-specialised object
+ */
 function isObject(value) {
     return (
         typeof value === "object" &&