docs(README.md): update

Author: sciborrudnicki

README.md

@@ -1501,6 +1501,8 @@ The **return value** is a `boolean` indicating whether or not the `value` is `un
 
 ### BigIntObject
 
+The object to create [`BigInt`][bigint] object by assign value to `set` property.
+
 ```typescript
 class BigIntObject {
   static set set(value: any) {
@@ -1516,6 +1518,8 @@ class BigIntObject {
 
 ### BooleanObject
 
+The object to create [`Boolean`][boolean] object by assign value to `set` property.
+
 ```typescript
 class BooleanObject {
   /**
@@ -1535,6 +1539,8 @@ class BooleanObject {
 
 ### NumberObject
 
+The object to create [`Number`][number] object by assign value to `set` property.
+
 ```typescript
 class NumberObject {
   static set set(value: any) {
@@ -1550,6 +1556,8 @@ class NumberObject {
 
 ### PrimitiveObject
 
+The object to store static primitive objects.
+
 ```typescript
 class PrimitiveObject  {
   static bigint: BigInt;
@@ -1564,6 +1572,8 @@ class PrimitiveObject  {
 
 ### StringObject
 
+The object to create [`String`][string] object by assign value to `set` property.
+
 ```typescript
 class StringObject {
   static set set(value: any) {
@@ -1579,6 +1589,8 @@ class StringObject {
 
 ### SymbolObject
 
+The object to create [`Symbol`][symbol] object by assign value to `set` property.
+
 ```typescript
 class SymbolObject {
   static set set(value: string | number | undefined) {