Add Parser API and remove panic from beautifier

[fmvilas]

What?

• Adds the parser API.
• Adds the ParsedAsyncAPI model and its fully-functional methods.
• Removes panic error from beautifier.
• Adds compilation script to compile to C shared object.

Fixes #3

Why?

To create an MVP of the parser. We can finally say this parser works, even though it's not yet ideal. We have a skateboard!

[fmvilas]

Had to change the API to make it compatible with C. Introduced a new package called cparser which is the one that exports the Parse method in C.

I tried using it from Node.js in Mac and it works beautifully :)

Will push the experiments on the Node.js side.

[fmvilas]

Here's the experimental Node.js code: https://github.com/asyncapi/parser-nodejs

[rmelian]

this is great :)