chore(injections)!: update injection syntax to 0.9

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

queries/julia/injections.scm

@@ -1,5 +1,5 @@
 ;; Inject markdown in docstrings 
-((string_literal) @markdown
+((string_literal) @injection.content
   . [
     (module_definition)
     (abstract_definition)
@@ -9,15 +9,18 @@
     (assignment)
     (const_statement)
   ]
- (#lua-match? @markdown "^\"\"\"")
- (#offset! @markdown 0 3 0 -3))
+ (#lua-match? @injection.content "^\"\"\"")
+ (#set! injection.language "markdown")
+ (#offset! @injection.content 0 3 0 -3))
 
-[
+([
   (line_comment)
   (block_comment)
-] @comment
+ ] @injection.content
+ (#set! injection.language "comment"))
 
 ((prefixed_string_literal
-   prefix: (identifier) @_prefix) @regex
+   prefix: (identifier) @_prefix) @injection.content
  (#eq? @_prefix "r")
- (#offset! @regex 0 2 0 -1))
+ (#set! injection.language "regex")
+ (#offset! @injection.content 0 2 0 -1))