📝 Mark xxxxxFileFormat functions as deprecated

Author: lambdalisue

denops_std/buffer/fileformat.ts

@@ -15,18 +15,24 @@ export type FileFormat = PredicateType<typeof isFileFormat>;
 
 /**
  * Assert that the value is FileFormat.
+ *
+ * @deprecated Use `assert` function of `unknownutil` instead.
  */
 export const assertFileFormat = (v: unknown): asserts v is FileFormat =>
   assert(v, isFileFormat);
 
 /**
  * Ensure that the value is FileFormat.
+ *
+ * @deprecated Use `ensure` function of `unknownutil` instead.
  */
 export const ensureFileFormat = (v: unknown): FileFormat =>
   ensure(v, isFileFormat);
 
 /**
  * Maybe that the value is FileFormat.
+ *
+ * @deprecated Use `maybe` function of `unknownutil` instead.
  */
 export const maybeFileFormat = (v: unknown): FileFormat | undefined =>
   maybe(v, isFileFormat);