Feature request: investigate how to improve highlighting

[AgustinSilverfin]

Is your feature request related to a problem? Please describe.
We want to improve highlighting of liquid in VSCode, including if possible Silverfin flavored liquid elements. We still need to investigate what is the best way to approach it.

Describe the solution you'd like
Every element in the code is highlighted properly. For example, custom drops: custom.foo.bar where namespace and key should be highlighted properly

Describe alternatives you've considered

• Investigate if it's possible (and viable) to use (and/or extend?) Shopify's tree-sitter https://github.com/Shopify/tree-sitter-liquid.
• Existing (deprecated) extension VS-Code for tree-sitter that may give some ideas on how to implement a new language. https://github.com/georgewfraser/vscode-tree-sitter

[AgustinSilverfin]

I've been playing around with tree-sitter, basically cloning Shopify's repo and trying to extend it. So I wrote the grammar rules for translations tags and I think I got something really interesting! This is how the tree of a liquid file looks and the items identified in translations (notice the highlighting on top of the translation key)

Picked up translations because I though it could be useful to address #54, but also could be done with parts and shared parts for #55 and so on!

[AgustinSilverfin]

Include tags to identify parts and shared parts