update README and CHANGELOG

CHANGELOG

@@ -1,3 +1,10 @@
+v4.0.0, released 2025-01-06
+    * support both 32 and 64 bases
+    * added Convert command between bases
+
+v2.0.0, released 2024-09-20 
+    * move to base 62
+
 v1.0.2, released 2024-08-08 
     * support negative values
 

README.md

@@ -2,7 +2,15 @@
 
 [![Build Status](https://drone.arns.lt/api/badges/zordsdavini/abcex/status.svg)](https://drone.arns.lt/zordsdavini/abcex)
 
-Computing system based on the number 62
+Computing system based on the number 62 or 36
+
+## Usage
+
+`Encode(int, int) -> string` - convert number into string based on given base.
+
+`Decode(string, int) -> int` - convert from encoded string into number based on given base.
+
+`Convert(string, int, int) -> string` - convert encoded string from one base to another.
 
 ## History