Add additional sections to development best practices

[ddobrin]

Additions to be added in:
https://doc.networknt.com/development/best-practices/

To cover best practices on:
exception handling, performance, dependency injection, etc.

[stevehu]

Yes. That is the idea. Currently, there is only one section for swagger and openapi specification. Once we have the content, we can add them to the same page with different sections.