Highlight FIDL keyword "service"

Change-Id: I28257987736efd846d80bdc2c901fcc792f69858
Reviewed-on: https://fuchsia-review.googlesource.com/c/fidlbolt/+/559061
Reviewed-by: Alex Zaslavsky <azaslavsky@google.com>
diff --git a/frontend/src/ace-modes.js b/frontend/src/ace-modes.js
index 38e5e85..b72d1d9 100644
--- a/frontend/src/ace-modes.js
+++ b/frontend/src/ace-modes.js
@@ -138,7 +138,7 @@
           },
           {
             token: 'keyword',
-            regex: /\b(?:alias|as|bits|box|compose|const|enum|flexible|library|optional|protocol|reserved|resource|strict|struct|table|type|union|using)\b/,
+            regex: /\b(?:alias|as|bits|box|compose|const|enum|flexible|library|optional|protocol|reserved|resource|service|strict|struct|table|type|union|using)\b/,
           },
           {
             token: 'support.type',