This PR prepares the release 1.17.0.

Summary by cubic

Prepares the axios 1.17.0 release by bumping version metadata and refreshing docs across locales. Adds Basic auth URL precedence notes, zstd decompression-bomb guidance, corrected TS signatures, and a ':surfer:' marker requirement in contributor templates; no runtime or API changes, no tests needed.

• Docs

  • Updated README and docs (en/es/fr/zh) to document Basic auth from URL and that explicit auth takes precedence.
  • Added zstd to security guidance and request-config notes.
  • Corrected API reference types for AxiosHeaders.toJSON and isCancel<T>.
  • Added ':surfer:' marker requirement in .github templates and contributor guides; verify /docs/ site badges and release notes reflect 1.17.0.

• Semantic version impact

  • Minor release (non-breaking).

^{Written for commit 6c3f8f9. Summary will update on new commits.}