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/c/injections.scm

@@ -1,10 +1,21 @@
-((preproc_def (preproc_arg) @c)
-  (#lua-match? @c "\n"))
-(preproc_function_def (preproc_arg) @c)
-(preproc_call (preproc_arg) @c)
+((preproc_def
+ (preproc_arg) @injection.content)
+ (#lua-match? @injection.content "\n")
+ (#set! injection.language "c"))
 
-(comment) @comment
+(preproc_function_def
+ (preproc_arg) @injection.content
+ (#set! injection.language "c"))
+
+(preproc_call
+ (preproc_arg) @injection.content
+ (#set! injection.language "c"))
+
+((comment) @injection.content
+ (#set! injection.language "comment"))
 
 ; TODO: add when asm is added
-; (gnu_asm_expression assembly_code: (string_literal) @asm)
-; (gnu_asm_expression assembly_code: (concatenated_string (string_literal) @asm))
+; (gnu_asm_expression assembly_code: (string_literal) @injection.content
+; (#set! injection.language "asm"))
+; (gnu_asm_expression assembly_code: (concatenated_string (string_literal) @injection.content)
+; (#set! injection.language "asm"))