docs(deepwiki): add deepwiki badge so it gets updated weekly (#3037)

Adds the deepwiki badge so that the documentation there gets updated
weekly

Author: rymnc

README.md

@@ -1,6 +1,7 @@
 # Fuel Client
 
 [![build](https://github.com/FuelLabs/fuel-core/actions/workflows/ci.yml/badge.svg)](https://github.com/FuelLabs/fuel-core/actions/workflows/ci.yml)
+[![deepwiki](https://deepwiki.com/badge.svg)](https://deepwiki.com/FuelLabs/fuel-core)
 [![crates.io](https://img.shields.io/crates/v/fuel-core?label=latest)](https://crates.io/crates/fuel-core)
 [![docs](https://docs.rs/fuel-core/badge.svg)](https://docs.rs/fuel-core/)
 [![discord](https://img.shields.io/badge/chat%20on-discord-orange?&logo=discord&logoColor=ffffff&color=7389D8&labelColor=6A7EC2)](https://discord.gg/xfpK4Pe)