Add java-prettify submodule

Test: bazelisk build //:gitiles && tools/run_dev.sh

Change-Id: I107354498367ec22e977e91f08e7de70d04b8573

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index b3e0d3f..95c5559 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -27,6 +27,12 @@
     path = "modules/jgit",
 )
 
+# Java-Prettify external repository consumed from git submodule
+local_repository(
+  name = "java-prettify",
+  path = "modules/java-prettify",
+)
+
 register_toolchains("//tools:error_prone_warnings_toolchain_java11_definition")
 
 register_toolchains("//tools:error_prone_warnings_toolchain_java17_definition")
@@ -68,13 +74,6 @@
     sha1 = "f7be08ec23c21485b9b5a1cf1654c2ec8c58168d",
 )
 
-# When upgrading prettify it should also be updated in plugins/gitiles
-maven_jar(
-    name = "prettify",
-    artifact = "com.github.twalcari:java-prettify:1.2.2",
-    sha1 = "b8ba1c1eb8b2e45cfd465d01218c6060e887572e",
-)
-
 COMMONMARK_VERSION = "0.10.0"
 
 # When upgrading commonmark it should also be updated in plugins/gitiles