docs: updating the link to server setup in CONTRIBUTING.md

[Mastermind-sap]

Description

The link in CONTRIBUTING.md to setup server is pointing to the wikis of the repo but there doesnot exist any wiki page related to the server setup. Updating it to point to the server setup options in readme untill the wikis are updated.

Checklist

• Tests have been added or updated to cover the changes
• Documentation has been updated to reflect the changes
• Code follows the established coding style guidelines
• All tests are passing

[SGI-CAPP-AT2]

I think it needs to be changed to this

- In order to use the mobile app, you would need the flood backend running on your local machine. There are several ways
- you can do that and all these approaches can be found at [Taskwarrior-Flutter](https://github.com/CCExtractor/taskwarrior-flutter/wiki)
+ You can setup taskserver to sync your tasks across clients
+ You can find the steps to setup one [here](https://github.com/CCExtractor/taskwarrior-flutter?tab=readme-ov-file#taskserver-setup).

[Mastermind-sap]

yeah that sounds accurate. Also I could not catch the meaning of flood backend in the previous version?

I have ammended the changes in the previous commit

[SGI-CAPP-AT2]

yeah that sounds accurate. Also I could not catch the meaning of flood backend in the previous version?

I have ammended the changes in the previous commit

looks like initial copied from flood mobile repo and never touched again

[Mastermind-sap]

yeah that sounds accurate. Also I could not catch the meaning of flood backend in the previous version?
I have ammended the changes in the previous commit

looks like initial copied from flood mobile repo and never touched again

oh now it makes sense. I believe the wikis are also copied from there as the folder structure and some lines hint towards that repo. ( like this torrent example )