feat(handler): add serve yaml

[zsbahtiar]

Describe the PR This PR aims to enhance the handler to serve yaml file.

Relation issue https://github.com/swaggo/http-swagger/issues/114

Additional context

Just wanne enhance the handler for serving swagger yaml like json

[zsbahtiar]

hi @ubogdan can you check my PR? thanks🙏🏻

[ubogdan]

@zsbahtiar Did you test code ? The http-swagger reads the documentation from swag doc instance which is the .go file that is generated in the docs folder.
This file only embeds the JSON version of the documentation as you may see here.