README: Add information on phase overrides

README.md

@@ -24,3 +24,36 @@ Options:
   --version                          Show version information
   -?, -h, --help                     Show help and usage information
 ```
+
+### Phase Override
+
+You can force the generator to override a specific phase at a certain time through an override phases JSON file.
+
+Here is an example of an override file:
+
+```
+{
+  "2024-09-03T02:00:00.0000000Z": {
+    "Length": 4,
+    "RegularStages": [
+      4,
+      8
+    ],
+    "GachiRule": 2,
+    "GachiStages": [
+      13,
+      15
+    ]
+  }
+}
+```
+
+This override forces the phase at `2024-09-03T02:00:00.0000000Z` to have the following characteristics:
+
+* 4 hours in length
+* Blackbelly Skatepark and Moray Towers in Regular Battle
+* Ancho-V Games and Mahi-Mahi Resort on Splat Zones in Ranked Battle
+
+While this example only contains one phase override, multiple overrides can be specified in a single file.
+
+For all possible values for `GachiRule`, consult the enum defined by `VersusRule.cs`. For a list of stage IDs, consult [this list](https://gist.github.com/OatmealDome/0028b73261ceb702f57531ea48eb7ae0#stages).