Clarify ClientRequestArgs.timeout units

[lunadogbot]

Summary

• Adds a focused Node reference generation annotation for http.ClientRequestArgs.timeout.
• Documents the timeout value as milliseconds on the generated property page.

Validation

• cd reference_gen && deno task types:node && deno task doc:node
• cd reference_gen && deno eval 'const files = JSON.parse(await Deno.readTextFile("gen/node.json")); const page = files["http/~/ClientRequestArgs.timeout.json"]; if (!page) throw new Error("missing page"); const text = JSON.stringify(page); if (!text.includes("Timeout in milliseconds.")) throw new Error("missing timeout docs"); console.log("verified ClientRequestArgs.timeout docs include milliseconds");'

Closes #3147

Closes bartlomieju/orchid-inbox#143