Hello ! I just needed to work with json but didn't remember all the json1 available functions and it's parameters so I went to https://www.sqlite.org/docs.html and did not found any mention to then, then I did a search https://www.sqlite.org/search?q=json and again nothing about then I remember that there is a compilation option to enable it so I went to https://www.sqlite.org/compile.html and there I found a link to https://www.sqlite.org/json1.html .
I think that the json1 functions are important enough to deserve a place on the top level documentation page https://www.sqlite.org/docs.html ! Cheers !