Add XML documentation for Org.Apache.Http #305

The Org.Apache.Http namespace contains 284 To be added placeholders in source XML documentation (excluding docs\xml\index.xml).

Finishability

Finishability: not assessed. The TODO count does not establish whether official Android/Java reference comments exist for every remaining member. A source-coverage pass is still needed; if the official comments are exhausted, use a separately agreed completion approach (for example, reviewed authored documentation based on an authoritative source) rather than another importer pass.

rg -n -i --glob 'Org.Apache.Http/**' --glob 'ns-Org.Apache.Http.xml' 'to be added' docs\xml

Update log

• 2026-10-02: Placeholder count rechecked at 284 (unchanged).
• 2026-09-10: Refreshed the placeholder scan from 278 to 284 (increased by 6). Related documentation PRs: #644.