docs: revisit and improve documentation of all packages

[shubhamp-sf]

• [x] docs: catalog root

Packages

• [x] #1442
• [ ] docs: @sourceloop/core
• [ ] docs: @sourceloop/cli
• [ ] docs: @sourceloop/feature-toggle
• [ ] docs: @sourceloop/search
• [ ] docs: @sourceloop/user-onboarding

Services

• [x] #1443
• [ ] docs: @sourceloop/authentication-service
• [ ] docs: @sourceloop/bpmn-service
• [ ] docs: @sourceloop/chat-service
• [ ] docs: @sourceloop/feature-toggle-service
• [ ] docs: @sourceloop/in-main-service
• [ ] docs: @sourceloop/notification-service
• [ ] docs: @sourceloop/oidc-service
• [ ] docs: @sourceloop/payment-service
• [ ] docs: @sourceloop/reporting-service
• [ ] docs: @sourceloop/scheduler-service
• [ ] docs: @sourceloop/search-service
• [ ] #1659
• [ ] docs: @sourceloop/video-conferencing-service