[docs] [issue27597] Add usage examples for TracebackException, StackSummary and FrameSummary

New submission from Ram Rachum: I saw these new interesting classes in the `traceback` docs, but if I were shown an example of how they are used, I might get inspired to use them in my own code. ---------- assignee: docs@python components: Documentation messages: 271072 nosy: cool-RR, docs@python priority: normal severity: normal status: open title: Add usage examples for TracebackException, StackSummary and FrameSummary type: enhancement versions: Python 3.5, Python 3.6 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue27597> _______________________________________