Firefly language support

This extension adds support for the Firefly programming language (.ff files). It should work out of the box with no configuration, and comes with the following features:

• Autocompletion
• Go to definition
• Find references
• Signature help
• Symbol renaming
• Document and workspace symbols
• Show type on hover
• Diagnostics
• Run in terminal

To install the Firefly compiler, run the following command in the terminal:
npm install -g firefly-compiler