profiles: add new djstrip profile

data/maps/default.json

@@ -1,6 +1,6 @@
 {
   "version": 1,
   "strides": [
-    {"x": 0, "y": 0, "pixels": 255}
+    {"x": 0, "y": 0, "pixels": 512}
   ]
 }

data/maps/djstrip.json

@@ -0,0 +1,6 @@
+{
+  "version": 1,
+  "strides": [
+    {"x": 0, "y": 0, "pixels": 50}
+  ]
+}