When creating a website it's always a good idea to create website documentation for that website.
The type of documentation that should be created for a website includes: end user documentation, website installation documentation and source code documentation.
End user documentation for a website is not always needed since websites are designed to be easy to use. It is, however, worth using standard navigation elements that users have come to expect, such as a top navigation bar, a side navigation bar and important legal links and a sitemap accessible from links at the bottom of a page. It's also worth including important user documentation such as a frequently asked questions and information about ordering processes in the case of ecommerce websites.