[docs] [issue29920] Document cgitb.text and cgitb.html

Serhiy Storchaka added the comment: I suggest to move the descriptions of text() and html() after handle(). And I don't know what to do with the discrepancy in the parameter name. ---------- versions: -Python 2.7, Python 3.5, Python 3.6 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue29920> _______________________________________