docs(fmt): improve documentation (#5373)

* docs(fmt): improve documentation

* work

* work

* work

fmt/README.md

@@ -0,0 +1,13 @@
+Provides utilities for formatting text of different types:
+
+- [Human-readable bytes](https://jsr.io/@std/fmt/doc/bytes/~)
+- [Styles for the CLI](https://jsr.io/@std/fmt/doc/colors/~)
+- [Time duration](https://jsr.io/@std/fmt/doc/duration/~)
+- [Printing formatted strings to stdout](https://jsr.io/@std/fmt/doc/printf/~)
+
+```ts
+import { format } from "@std/fmt/bytes";
+import { red } from "@std/fmt/colors";
+
+console.log(red(format(1337))); // Prints "1.34 kB"
+```

fmt/bytes.ts

@@ -4,6 +4,22 @@
 // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
 // This module is browser compatible.
 
+/**
+ * Convert bytes to a human-readable string: 1337 → 1.34 kB
+ *
+ * Based on {@link https://github.com/sindresorhus/pretty-bytes | pretty-bytes}.
+ * A utility for displaying file sizes for humans.
+ *
+ * ```ts
+ * import { format } from "@std/fmt/bytes";
+ * import { assertEquals } from "@std/assert";
+ *
+ * assertEquals(format(1337), "1.34 kB");
+ * assertEquals(format(100), "100 B");
+ * ```
+ * @module
+ */
+
 type LocaleOptions = {
   minimumFractionDigits?: number;
   maximumFractionDigits?: number;

fmt/colors.ts

@@ -6,6 +6,11 @@
 /**
  * String formatters and utilities for dealing with ANSI color codes.
  *
+ * > ![IMPORTANT]
+ * > If printing directly to the console, it's recommended to style console
+ * > output using CSS (guide
+ * > {@linkcode https://developer.mozilla.org/en-US/docs/Web/API/console#styling_console_output | here}).
+ *
  * This module supports `NO_COLOR` environmental variable disabling any coloring
  * if `NO_COLOR` is set.
  *