Encoding options

[simonprev]

Hi, thanks for this lib. It seems that this is the only erlang/elixir library with "encoding" support 😄 (From a data structure to actual YAML content).

It seems that there are no options when encoding values.

• Double quotes around values. This could optional and only done when the content needs to have quote to be valid.
• Keys as atom. The only way to not print the keys inside double quotes is to use atom.
• Data type casting for value like "true", "false"...

I don’t know if this make sense for this library, feel free to close if it is not in the scope of the project.

Thank you!