Docs/55 misc documentation

[rkandoi]

What type of PR is this?

Add one of the following kinds:

• documentation

Which issue(s) this PR fixes:

Fixes #55

Special notes for reviewers:

• Removed the version number from info.description (belongs in info.version)
• Expanded the Pre-requisites section (consumer/provider agreements, activation code source, FQDN discovery)
• Added blank line after the SGML BEGIN markers so headings render
• Normalized "eSIM Management API" → "eSIM Profile Management API"
• Added a device-connectivity prerequisite: target device must be reachable for over-the-air operations (spec + General Description + test)