knitr supports only one documentation language.

HTML is a markup language that is used to create web pages. It is a set of tags that are used to define the structure and content of a web page.

LaTeX is a document preparation system that is used to create documents that are typeset in a professional manner. It is often used for creating academic papers, books, and other documents that require a high level of typographic quality.

R Markdown is a markup language that is used to create documents that contain both R code and formatted text. It is often used for creating reports, presentations, and other documents that require the use of R code.

Knitr is a tool that can be used to create dynamic documents from R code. It can be used to create documents in a variety of formats, including Markdown, HTML, LaTeX, and R Markdown.