Add tree-sitter queries.

runtime/queries/bash/highlights.scm

@@ -0,0 +1,54 @@
+[
+  (string)
+  (raw_string)
+  (heredoc_body)
+  (heredoc_start)
+] @string
+
+(command_name) @function
+
+(variable_name) @property
+
+[
+  "case"
+  "do"
+  "done"
+  "elif"
+  "else"
+  "esac"
+  "export"
+  "fi"
+  "for"
+  "function"
+  "if"
+  "in"
+  "unset"
+  "while"
+  "then"
+] @keyword
+
+(comment) @comment
+
+(function_definition name: (word) @function)
+
+(file_descriptor) @number
+
+[
+  (command_substitution)
+  (process_substitution)
+  (expansion)
+]@embedded
+
+[
+  "$"
+  "&&"
+  ">"
+  ">>"
+  "<"
+  "|"
+] @operator
+
+(
+  (command (_) @constant)
+  (#match? @constant "^-")
+)