Make it a unified open source repo for Phala Cloud

[h4x3rotab]

• Merge Phala-Network/phala-cloud-community to this repo (@h4x3rotab)
• Merge Phala-Network/awesome-phala-cloud to this repo (@kingsleydon)
• Merge Phala-Network/phala-cloud-cli to this repo (@mondaylord)
• Exclude unrelated changes to trigger .github/workflows (@Leechael)
• Reconstruct the docs of this repo (@HashWarlock)
• Make it AI friendly (@HashWarlock)
• Migrate Phala Cloud docs (@HashWarlock)