docs: #192 Express sample app documentation improvements and renames to README.md

[TheRealAgentK]

docs: #192 (Express sample app documentation improvements and renames to README.md)

Description 📝

• Purpose: Fixes Express sample README improvements #192, improves documentation and file name consistency across the samples and main project
• Approach: n/a

Type of change

• This change requires a documentation update (in fact it IS a documentation update only)

Updates

👉 Changed content of express sample README
👉 Renamed all other sample readme files to README to make it consistent with main project

Test plan 🧪

n/a

Author to check 👓

• Project and all contained modules builds successfully
• Self-/dev-tested
• Unit/UI/Automation/Integration tests provided where applicable
• Code is written to standards
• Appropriate documentation written (code comments, internal docs)

Reviewer to check ✔️

• Project and all contained modules builds successfully
• Change has been dev-/reviewer-tested, where possible
• Unit/UI/Automation/Integration tests provided where applicable
• Code is written to standards
• Appropriate documentation written (code comments, internal docs)

[sumitramanga]

LGTM 🌮