Tweak the import tree sitter hlgroups.

(This still isn't really used yet until/unless tree-sitter-lean is
revived. But the hlgroup is wrong as-is so may as well fix it.)

Author: Julian

queries/lean/highlights.scm

@@ -68,7 +68,8 @@
 
 ["for" "in" "do"] @repeat
 
-(import) @include
+(import
+  module: (identifier) @module)
 
 ; Tokens
 
@@ -173,6 +174,10 @@
   (trivial)
 ] @keyword
 
+[
+ "import"
+] @keyword.import
+
 [
   "catch"
   "finally"