docs: update namespace TypeScript declarations

[stdlib-bot]

This PR

• updates namespace TypeScript declarations

Reviewer Checklist

• Check the scope of the changes (following Conventional Commits):
  • Are these new APIs? Then this is a feat.
  • Are these changes to existing APIs that could break compatibility? Then this is a feat! (i.e., a breaking change).
  • Are these only documentation changes to existing APIs? Then this is docs.
• Update the PR title to align with the change type (feat, feat!, or docs).
• Approve the PR once you are confident about the classification and changes made.

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base	$\color{green}1968/1968$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}0/0$ $\color{green}+100.00\%$	$\color{green}1968/1968$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.