Add documentation on how to use unicode

[gunthercox]

It would be useful to have some documentation on how to use unicode encoding in Python and how troubleshoot unicode errors and warnings. ChatterBot's domain involves working with string type data and a variety of unicode-related questions come up frequently.

[vkosuri]

@gunthercox a useful tag,

I want share some of my thoughts here, If i found unicode issues how i resolved those issues

Recommended use virtual environments for python2 and python3.

python2

virtualenv venv
source venv/bin/activate
python chatterbot-example.py

python3

python3 -m venv /path/to/new/virtual/environment
source venv/bin/activate
python chatterbot-example.py

1. Learn the differences between Python 2 & 3
2. Use Futurize (or Modernize) to update your code (e.g. pip install future)
3. Use Pylint to help make sure you don’t regress on your Python 3 support (pip install pylint)
4. Use caniusepython3 to find out which of your
5. Consider using optional static type checking to make sure your type usage works in both Python 2 & 3 (e.g. use mypy to check your typing under both Python 2 & Python 3).