Since 0.9, @lang syntax is still available as fallback but will soon be deprecated.
Because of that, new syntax should be adopted once 0.9 becomes the
baseline requirements for nvim-treesitter
- update health check
- update doc
After https://github.com/nvim-treesitter/nvim-treesitter/issues/470,
we decided to use `@conditional` for ternary operator instead of
operator despite `@conditional` is documented for keywords only.
A sub-scoping can make it easier for people to highlight this operator
group differently.
Also unify the usage of `@conditional...` across languages.
