fix: preserve backward compatibility

Author: mirek

src/index.ts

@@ -99,5 +99,9 @@ export {
   undefined_ as undefined,
   undefinedOr,
   unique,
-  unknown
+  unknown,
+
+  // Backward compatibility:
+  nullish as nil,
+  nullishOr as nilOr
 }

src/prelude.ts

@@ -20,6 +20,12 @@ export type Awaited<T> =
 export type Keyed<T = unknown> =
   Record<string, T | undefined>
 
+/** @deprecated use {@link Nullish} */
+export type NilOr<T> =
+  | undefined
+  | null
+  | T
+
 export type Nullish<T> =
   | undefined
   | null