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.
• 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