add grocery-transactions as submodule

.gitmodules

@@ -2,3 +2,8 @@
 	path = prayer-generator
 	url = https://gogs.shandan.one/gogsadmin/prayer-generator.git
 	branch = master
+
+[submodule "grocery-transactions"]
+	path = grocery-transactions
+	url = /home/pi/git/grocery_transactions.git
+	branch = master

grocery-transactions

@@ -0,0 +1 @@
+Subproject commit 0a6c6f745ce8becc7baa42e15c1be1d40ce05318