Highlight jinja2 syntax

Change-Id: I1b0bb5c09de0d5f16c72eb820b60f1c435af3cbe
diff --git a/gerrit-server/src/main/resources/com/google/gerrit/server/mime/mime-types.properties b/gerrit-server/src/main/resources/com/google/gerrit/server/mime/mime-types.properties
index baf1753..99049e7 100644
--- a/gerrit-server/src/main/resources/com/google/gerrit/server/mime/mime-types.properties
+++ b/gerrit-server/src/main/resources/com/google/gerrit/server/mime/mime-types.properties
@@ -98,9 +98,12 @@
 in = text/x-properties
 ini = text/x-properties
 intr = text/x-dylan
+j2 = text/x-jinja2
 jade = text/x-pug
 java = text/x-java
 Jenkinsfile = text/x-groovy
+jinja = text/x-jinja2
+jinja2 = text/x-jinja2
 jl = text/x-julia
 jruby = text/x-ruby
 js = text/javascript