v3.0.0-beta.1

changes README's hello-world example for v3 (#698)

* [doc] adding graceful documentation and example.

* adding myself to the maintainers list and minor comment formatting change

* [doc] updating code on the guides/context.md and guides/cookies.md to use v3 code.

* [doc] updating error-handling and request to v3 codebase

* [doc] updating templates documentation

* [doc] cleaning hello-world documentation for v3

* [content] adding website index content based on #667