Update Valley slug. Add ImpromptuModular. (#349)

.gitmodules

@@ -98,7 +98,7 @@
 	url = https://github.com/squinkylabs/SquinkyVCV
 	branch = master
 [submodule "repos/ValleyFree"]
-	path = repos/ValleyFree
+	path = repos/Valley
 	url = https://github.com/ValleyAudio/ValleyRackFree.git
 	branch = v0.6
 [submodule "repos/CharredDesert"]
@@ -165,3 +165,7 @@
 	path = repos/cf
 	url = https://github.com/cfoulc/cf
 	branch = master
+[submodule "repos/ImpromptuModular"]
+	path = repos/ImpromptuModular
+	url = https://github.com/MarcBoule/ImpromptuModular.git
+	branch = master

repos/ImpromptuModular

@@ -0,0 +1 @@
+Subproject commit 6933a9ba95c43fa4b446dfb7251b4d13155d6e30