Added section & environment folding to the latex parser

[Nidish96]

I've added section (& subsection, ...) and environment (generic_environment & math_environment) folding to the latex parser.

[jcs090218]

Can you forward declare functions at the very top. See

https://github.com/emacs-tree-sitter/ts-fold/blob/59c57057ba892e169510052d59921b8b3090fce9/ts-fold-parsers.el#L38-L97

Make sure there is no compile error:

ts-fold-parsers.el:509:8: Warning: function `ts-fold-parsers-matlab' defined multiple times in this file

You can use Eask to do the clean compilation. See the development section for more information.

[Nidish96]

Thank you for the quick feedback! I've fixed the issues in the latest commits. Cheers!

[Nidish96]

Apologies - done now.

[jcs090218]

Thank you!