Update changelog + readme

CHANGELOG.md

 # Changelog of coloration-lib
 
+## V0.0.3 (2019-01-22)
+
+### Features
+
+- add `maskColor` and  `maskOpacity` params for `addColor()`
+
 ## V0.0.2 (2019-01-21)
 
-### Changes
+### Features
 
 - add `getRGB()` and `getHSV()` methods
 

README.md

@@ -21,11 +21,29 @@ Only for demo:
 
 ## Usage
 
-Example:
+### Examples 
+
+#### changeLuminosity
 
 ```typescript
 import {Coloration} from 'coloration-lib';
 
+const color = new Coloration('red');
+color.changeLuminosity(0.55);
+console.log(color.toHEX()); // #ff8c8c 
+```
+
+#### maskColor
+
+```typescript
+const color = new Coloration('red');
+color.maskColor('blue', 0.25);
+console.log(color.toHEX()); // #bf0040
+```
+
+#### addColor
+
+```typescript
 const color = new Coloration('red');
 color.addColor({
     h: -23,