Update first part of article 'Descriptor-HOW-TO-Guide.rst'.
Fix typo.
Merge branch 'master' of github.com:iceout/PyZh

Conflicts:
	docs/Descriptor-HOW-TO-Guide.rst
Complete 1.6 section.
Update Descriptor-HOW-TO-Guide.rst.
Merge pull request #1 from iceout/Update_descriptor

Update Descriptor-HOW-TO-Guide.rst