docs(pt): translate handbook-v2/More on Functions

[guuszz]

Summary

Adds the Brazilian Portuguese translation of More on Functions from the TypeScript v2 Handbook, into docs/documentation/pt/handbook-v2/.

This continues the handbook-v2 PT-BR effort (#247–#251). More on Functions is page #5 in the reading order — it's a dense, central page covering function type expressions, call/construct signatures, generic functions (inference, constraints, guidelines), optional parameters, overloads, this, the void/object/unknown/never/Function types, rest parameters/arguments and parameter destructuring.

Translation choices

• Followed the established pt/ frontmatter convention: translated title and oneline, adapted permalink to /pt/docs/handbook/2/functions.html.
• Preserved every code sample verbatim — all 16 @errors directive lines (14 groups, verified identical to EN), every // ---cut--- (13), both // ^? markers, the in-code // prettier-ignore pragma and both // @ts-expect-error directives (left untranslated — they're functional).
• Preserved the two <blockquote class='bg-reading'> background-reading boxes: translated the "Background Reading" label to "Leitura de apoio" and kept the MDN links unchanged.
• Kept the <!-- prettier-ignore --> and <!-- TODO --> HTML comments.
• Translated only the explanatory comments inside code blocks; identifiers, strings and sample values left unchanged.
• Kept technical terms with a PT gloss on first use (e.g. assinatura de chamada (call signature), restrição (constraint), sobrecargas (overloads), parâmetros rest).

Source

microsoft/TypeScript-Website @ packages/documentation/copy/en/handbook-v2/More on Functions.md

Testing

Read side-by-side with the EN source; verified code fences (108), ---cut--- (13), ^? (2), @ts-expect-error (2) and bg-reading blockquotes (2) match, and a diff of all @errors codes between EN and PT is empty. Cross-checked terminology against the already-merged pt/ pages and my sibling PRs (#247–#251).