docs: fix typo in comment on InitParam (#1841)

Author: gzm0

packages/openapi-fetch/src/index.d.ts

@@ -160,7 +160,7 @@ export type MaybeOptionalInit<Params extends Record<HttpMethod, {}>, Location ex
 // The final init param to accept.
 // - Determines if the param is optional or not.
 // - Performs arbitrary [key: string] addition.
-// Note: the addition It MUST happen after all the inference happens (otherwise TS can’t infer if init is required or not).
+// Note: the addition MUST happen after all the inference happens (otherwise TS can’t infer if init is required or not).
 type InitParam<Init> = RequiredKeysOf<Init> extends never
   ? [(Init & { [key: string]: unknown })?]
   : [Init & { [key: string]: unknown }];