Syntax highlighting for Tact and FunC

[novusnota]

TON Docs also use Docusaurus doc framework and Prism.js for syntax highlighting.

See:

• How to add additional languages: https://docusaurus.io/docs/markdown-features/code-blocks#supported-languages
• How TON Docs did it: https://github.com/ton-community/ton-docs/tree/main/src/theme
• Fresh Tact and FunC syntax definitions: feat: update Prism.js definitions of Tact and FunC for syntax highlighting ton-community/ton-docs#768