Add some playoff constants for mapping and labeling

src/domain/playoffs.py

@@ -0,0 +1,15 @@
+PLAYOFF_WEEK_TO_SCHEDULE_WEEK = {
+    1: 19,
+    2: 20,
+    3: 21,
+    4: 22,
+}
+
+PLAYOFF_WEEK_TO_NAME = {
+    1: "Wildcard",
+    2: "Divisional",
+    3: "Conference",
+    4: "Super Bowl",
+}
+
+CURRENT_PLAYOFF_WEEK = 1