Add subscriptions resource bundle

.gitignore

@@ -23,4 +23,6 @@ deployer-production.properties
 deployer.log
 /service/src/main/resources/org/signal/badges/Badges_*.properties
 !/service/src/main/resources/org/signal/badges/Badges_en.properties
+/service/src/main/resources/org/signal/subscriptions/Subscriptions_*.properties
+!/service/src/main/resources/org/signal/subscriptions/Subscriptions_en.properties
 /.tx/config

service/src/main/resources/org/signal/subscriptions/Subscriptions.properties

@@ -0,0 +1,13 @@
+#
+# Copyright 2021 Signal Messenger, LLC
+# SPDX-License-Identifier: AGPL-3.0-only
+#
+
+# First subscription level
+SUSTAINER1 = Sustainer 1
+
+# Second subscription level
+SUSTAINER2 = Sustainer 2
+
+# Third subscription level
+SUSTAINER3 = Sustainer 3