Update Hash extension installation notes (php#4867)

Author: joshtrichards

reference/hash/setup.xml

@@ -8,17 +8,15 @@
  <section xml:id="hash.installation">
   &reftitle.install;
   <para>
-   As of PHP 5.1.2, the Hash extension is bundled and compiled into PHP by
-   default.
+   The Hash extension is a core PHP extension, so it is always enabled.
   </para>
   <para>
-   It may be explicitly disabled by using the --disable-hash switch to
-   configure.  Earlier versions of PHP may incorporate the Hash extension by
-   installing the
-   <link xlink:href="&url.pecl.package;hash">PECL module</link>.
+   Prior to PHP 7.4.0, the Hash extension was bundled and compiled into PHP by
+   default, but could be explicitly disabled using <option role="configure">--disable-hash</option>.
   </para>
   <para>
-   As of PHP 7.4.0, the Hash extension is a core PHP extension, so it is always enabled.
+   Prior to 5.1.2, the Hash extension was installed as a
+   <link xlink:href="&url.pecl.package;hash">PECL module</link>.
   </para>
  </section>
  <!-- }}} -->