[#69] Add docstring for Site.api()
[#69] Add docstring for Site.api()

Jobava/mirror-mwclient,danmichaelo/mwclient,PierreSelim/mwclient,mwclient/mwclient,JeroenDeDauw/mwclient,AdamWill/mwclient,ubibene/mwclient