Elixir: Add defdelagate keyword and for function/module name

[matthewlehner]

This is my first PR here. Hopeful that I've followed the guidelines properly!

This adds support for:

• modules (aliased as class-name)
• function names in definitions
• defdelegate is added as a keyword

Here's a screenshot of the "module attributes" example with the module name and function name properly highlighted:

[github-actions]

JS File Size Changes (gzipped)

A total of 1 files have changed, with a combined diff of +72 B (+9.5%).

file	master	pull	size diff	% diff
components/prism-elixir.min.js	761 B	833 B	+72 B	+9.5%

Generated by 🚫 dangerJS against 56bcafa

[RunDevelopment]

Thank you for contributing @matthewlehner!