[Docs]: coffee-agntcy/slim-coffee-agntcy.md contains incorrect links

[lgecse]

Issue Description

Identified by #243, there are some invalid urls in the CoffeeAgntcy docs:

WARNING -  htmlproofer: invalid url -
           https://github.com/agntcy/coffeeAgntcy/blob/main/coffeeAGNTCY/coffee_agents/lungo/exchange/graph/tools.py
           [404] [coffee-agntcy/slim-coffee-agntcy.md]
WARNING -  htmlproofer: invalid url -
           https://github.com/agntcy/coffeeAgntcy/blob/main/coffeeAGNTCY/coffee_agents/lungo/farms/brazil/farm_server.py
           [404] [coffee-agntcy/slim-coffee-agntcy.md]

Prposed Solution

Fix links to point to the actual content.

Affected Component

Other

Checklist

• I have read the contributing guidelines.
• I have verified this does not duplicate an existing issue.