all: remove koka code, move go to repo root

aptitudelevel_string.go

@@ -0,0 +1,31 @@
+// Code generated by "stringer -type AptitudeLevel -trimprefix AptitudeLv"; DO NOT EDIT.
+
+package horse
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[AptitudeLvG-1]
+	_ = x[AptitudeLvF-2]
+	_ = x[AptitudeLvE-3]
+	_ = x[AptitudeLvD-4]
+	_ = x[AptitudeLvC-5]
+	_ = x[AptitudeLvB-6]
+	_ = x[AptitudeLvA-7]
+	_ = x[AptitudeLvS-8]
+}
+
+const _AptitudeLevel_name = "GFEDCBAS"
+
+var _AptitudeLevel_index = [...]uint8{0, 1, 2, 3, 4, 5, 6, 7, 8}
+
+func (i AptitudeLevel) String() string {
+	idx := int(i) - 1
+	if i < 1 || idx >= len(_AptitudeLevel_index)-1 {
+		return "AptitudeLevel(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _AptitudeLevel_name[_AptitudeLevel_index[idx]:_AptitudeLevel_index[idx+1]]
+}