Improve documentation

[Chief-Rishab]

Guardian documentation should have a Guide section with the following guides:

• [ ] Create a troubleshooting guide.
• [ ] Create a detailed policy creation guide that walks through detailed policy creation and covers all advanced features.
• [x] Add a deployment guide for adding a new provider on Guardian
• [ ] Create a detailed appeal creation guide
• [ ] Create a detailed deployment guide

Concepts:

• [ ] Create a detailed concept guide for appeal, policy, and providers.
• [ ] Update diagrams for better representation.

References:

• [ ] Add config reference for server and client configs