Provide best practices description

[smolnikov]

Readme says this linter is to:

encourage API developers to use best practices and avoid anti-patterns

but there's no links to the description of how these best practices should work and how avoiding them can affect proxy quality or result in bugs.

I suggest to add the links to best practices description in Apigee docs/community forum or create wiki pages with each practice description.

[apetrosian]

Good idea, here is a good starting point:
https://community.apigee.com/articles/44662/the-book-of-apigee-edge-antipatterns.html

[smolnikov]

One more link to use
https://docs.apigee.com/api-platform/fundamentals/best-practices-api-proxy-design-and-development

[yuryninog]

Hi! I have created a PR adding those links to the README #288
CC: @gbrail