Concept: Extend functions with more examples and docs

[yznts]

• [x] Use
• [x] Await
• [x] ComponentName
• [x] MarshalState
• [x] UnmarshalState
• [x] HandlePage
• [x] HandlerPage
• [x] Serve
• [x] Template
• [x] TemplateInline
• [x] TemplateRaw