Add JSON input (#3)

Co-authored-by: Smaug123 <patrick+github@patrickstevens.co.uk>
Reviewed-on: #3

AnkiStatic.Lib/Domain/Grave.fs

@@ -0,0 +1,19 @@
+namespace AnkiStatic
+
+type GraveType =
+    | Card
+    | Note
+    | Deck
+
+    member this.ToInteger () =
+        match this with
+        | GraveType.Card -> 0
+        | GraveType.Note -> 1
+        | GraveType.Deck -> 2
+
+type Grave =
+    {
+        UpdateSequenceNumber : int
+        ObjectId : int
+        Type : GraveType
+    }