expanded codecaption functionality

[wolfspyre]

Thanks for sharing your shortcodes. Quite useful!!

This PR expands the codecaption shortcode functionality by allowing user to specify options to feed highlight.

Additionally adds the option to display the language name in the rendered output.

[parsiya]

Apologies for the delay in response.

Thanks for the PR and teaching me a great way to pass options to shortcodes. My shortcodes are so old they could be starting school right now.

Do you wanna make another commit and add your name to the file before I merge this?

Note to self: Add the showlang option for codecaption and add a second image to showcase it.

[wolfspyre]

nah. I noticed that it's not working the way I'd hoped it would anymore.... seems like something changed in the option logic in the last few hugo vers. as soon as I get around to fixing I'll submit a fix.... but I don't need credit... youve helped me a bunch with your bits n pieces! Thank you!