feat(README.md): usage of cli tool

README.md

@@ -13,6 +13,7 @@ c++ encoding/decoding from arbitrary base
 
 - [Installation](#installation)
 - [Documentation](#documentation)
+- [Usage](#usage)
 - [Contributing](#contributing)
 
 ## Installation
@@ -35,6 +36,19 @@ sudo make uni USRDIR=(Your installation dir)
 
 Available [here](https://vsek1ro.github.io/libbasen)
 
+## Usage
+
+libbasen package provides `basen` cli tool. Below are examples of use:
+```
+echo "hello world" | basen -t hex > encoded.data
+```
+```
+basen -t hex -d < encoded.data > decoded.data
+```
+```
+echo "arbitrary alphabet" | basen -a "0123ABCD"
+```
+
 ## Contributing
 
 Main branch is under protection rules, so you should create pull request. After merging will be runned [authors.sh](https://github.com/vSEK1RO/libbasen/blob/main/authors.sh) for adding all contributors usernames and their number of commits to [AUTHORS](https://github.com/vSEK1RO/libbasen/blob/main/AUTHORS) file.