No link to api docs from main documentation

[othercorey]

The main documentation has a header that points to the main cake php api/book documentation and not the chronos api documentation.

https://book.cakephp.org/chronos/1.x/en/

You have to open the github readme page to find the link to the api docs. I think adding it to the side-bar in contents.rst probably makes sense, but I don't know what you intended.

[markstory]

Having a link from the docs to the API seems like a good idea to me.

[saeideng]

also could be useful to rename api to core api or something like this in header PR open ,so closing