Add columbus (#342)

<!-- Thanks for making Ratatui awesome! 🐭 -->

* Link to the project: <!-- paste here -->
GitHub: https://github.com/sivaprakashkrp/columbus
crates.io: https://crates.io/crates/columbus

* Description:  <!-- short summary -->
`columbus` is a GUI-like TUI File explorer written in Ratatui and Rust.
It can explore drives, open files on `enter` through user-defined
configuration in `file_options.toml`. `columbus` also maintains your
frequently visited directories and helps you to reach them quicker
through a Quick-Access Menu.

* Screenshot: <!-- drag & drop or link -->

<img width="1458" height="704" alt="image"
src="https://github.com/user-attachments/assets/57b21134-3758-40f5-910e-a22a3304c9bd"
/>

Author: sivaprakashkrp

README.md

@@ -314,6 +314,7 @@ Aside from those listed here, many other apps and libraries can be easily be fou
 - [btlescan](https://github.com/ztroop/btlescan) - Bluetooth Low Energy (BTLE) scanner and GATT viewer.
 - [budget_tracker_tui](https://github.com/Feromond/budget_tracker_tui) - A fast, keyboard-driven TUI for tracking expenses, managing categories, and analyzing your budget with ease.
 - [chamber](https://github.com/mikeleppane/chamber) - A TUI for managing secrets.
+- [columbus](https://github.com/sivaprakashkrp/columbus) - A GUI-like TUI file explorer.
 - [csvlens](https://github.com/YS-L/csvlens) - Command line csv viewer.
 - [ddv](https://github.com/lusingander/ddv) - Terminal DynamoDB viewer.
 - [dead-ringer](https://github.com/ztroop/dead-ringer) - Binary diff tool for Hex/ASCII analysis.