Fix highlighting in string escapes for emacs tree-sitter-mode

tree-sitter-mode seems a bit picky about the order in which
expressions are listed in highlights.scm and won't highlight
expressions inside string escapes correctly without this change.

queries/highlights.scm

@@ -1,14 +1,14 @@
 (comment) @comment
 
 [
-  "if" 
+  "if"
   "then"
   "else"
   "let"
   "inherit"
   "in"
   "rec"
-  "with" 
+  "with"
   "assert"
   "or"
 ] @keyword
@@ -21,28 +21,11 @@
  (#match? @function.builtin "^(__add|__addErrorContext|__all|__any|__appendContext|__attrNames|__attrValues|__bitAnd|__bitOr|__bitXor|__catAttrs|__compareVersions|__concatLists|__concatMap|__concatStringsSep|__deepSeq|__div|__elem|__elemAt|__fetchurl|__filter|__filterSource|__findFile|__foldl'|__fromJSON|__functionArgs|__genList|__genericClosure|__getAttr|__getContext|__getEnv|__hasAttr|__hasContext|__hashFile|__hashString|__head|__intersectAttrs|__isAttrs|__isBool|__isFloat|__isFunction|__isInt|__isList|__isPath|__isString|__langVersion|__length|__lessThan|__listToAttrs|__mapAttrs|__match|__mul|__parseDrvName|__partition|__path|__pathExists|__readDir|__readFile|__replaceStrings|__seq|__sort|__split|__splitVersion|__storePath|__stringLength|__sub|__substring|__tail|__toFile|__toJSON|__toPath|__toXML|__trace|__tryEval|__typeOf|__unsafeDiscardOutputDependency|__unsafeDiscardStringContext|__unsafeGetAttrPos|__valueSize|abort|baseNameOf|derivation|derivationStrict|dirOf|fetchGit|fetchMercurial|fetchTarball|fromTOML|import|isNull|map|placeholder|removeAttrs|scopedImport|throw|toString)$")
  (#is-not? local))
 
-[
-  (string_expression)
-  (indented_string_expression)
-] @string
-
-[
-  (path_expression)
-  (hpath_expression)
-  (spath_expression)
-] @string.special.path
-
-(uri_expression) @string.special.uri
-
 [
   (integer_expression)
   (float_expression)
 ] @number
 
-(interpolation
-  "${" @punctuation.special
-  "}" @punctuation.special) @embedded
-
 (escape_sequence) @escape
 (dollar_escape) @escape
 
@@ -96,3 +79,21 @@
 ] @punctuation.bracket
 
 (identifier) @variable
+
+[
+  (string_expression)
+  (indented_string_expression)
+] @string
+
+[
+  (path_expression)
+  (hpath_expression)
+  (spath_expression)
+] @string.special.path
+
+(uri_expression) @string.special.uri
+
+(interpolation
+  "${" @punctuation.special
+  (_) @embedded
+  "}" @punctuation.special)