Update README.md

Author: setanarut

README.md

@@ -4,16 +4,30 @@ Command line tool to convert photos into pointillist painting
 
 ![banner Orta](https://github.com/user-attachments/assets/9f704a03-7dfe-46b8-a7e9-41961caba866)
 
-## Installation
+## Command line tool installation
 
-// todo
+```Zsh
+go install github.com/setanarut/pointilizm/v2/cmd/pnt@latest
+```
+
+## Usage
+
+Supported formats are PNG and JPG
+
+```Zsh
+pnt input.jpg output.jpg
+```
 
 ## Samples
 
+input 1
 ![input1](https://github.com/user-attachments/assets/1151952f-a9ae-48e0-9956-936be5787047)
 
+output 1
 ![output1](https://github.com/user-attachments/assets/4fdc016b-9d13-4c1a-8a26-849f415a908a)
 
+input 2
 ![input2](https://github.com/user-attachments/assets/b455999e-b923-4c8a-87b8-cfc89c1e7b91)
 
+output 2
 ![output2](https://github.com/user-attachments/assets/127d40e7-0722-410e-b928-85ba752b4673)