docs: make types more specific

Author: kenjis

system/HTTP/Header.php

@@ -28,15 +28,23 @@ class Header
     /**
      * The value of the header. May have more than one
      * value. If so, will be an array of strings.
+     * E.g.,
+     *   [
+     *       'foo',
+     *       [
+     *           'bar' => 'fizz',
+     *       ],
+     *       'baz' => 'buzz',
+     *   ]
      *
-     * @var array<array<string>|string>|string
+     * @var array<int|string, array<string, string>|string>|string
      */
     protected $value;
 
     /**
      * Header constructor. name is mandatory, if a value is provided, it will be set.
      *
-     * @param array<array<string>|string>|string|null $value
+     * @param array<int|string, array<string, string>|string>|string|null $value
      */
     public function __construct(string $name, $value = null)
     {
@@ -56,7 +64,7 @@ public function getName(): string
      * Gets the raw value of the header. This may return either a string
      * of an array, depending on whether the header has multiple values or not.
      *
-     * @return array<array<string>|string>|string
+     * @return array<int|string, array<string, string>|string>|string
      */
     public function getValue()
     {
@@ -78,7 +86,7 @@ public function setName(string $name)
     /**
      * Sets the value of the header, overwriting any previous value(s).
      *
-     * @param array<array<string>|string>|string|null $value
+     * @param array<int|string, array<string, string>|string>|string|null $value
      *
      * @return $this
      */