add docs for crazywhalecc/static-php-cli#444

Author: crazywhalecc

docs/en/guide/extension-notes.md

@@ -144,3 +144,7 @@ please download the source code from [pecl.php.net/package/xhprof](http://pecl.p
 If you enable event extension on macOS, the `openpty` will be disabled due to issue:
 
 - [static-php-cli#335](https://github.com/crazywhalecc/static-php-cli/issues/335)
+
+## parallel
+
+Parallel is only supported on PHP 8.0 ZTS and above.

docs/extensions.md

@@ -38,6 +38,7 @@
 | [oci8](./extension-notes#oci8)                             | no            | no             | no            |               |
 | opcache                                                    | yes           | yes            | yes           | yes           |
 | [openssl](./extension-notes#openssl)                       | yes           | yes            | yes           | yes           |
+| [parallel](./extension-notes#parallel)                     | yes           | yes            |               | yes           |
 | [password-argon2](./extension-notes#password-argon2)       | yes           | yes            |               |               |
 | pcntl                                                      | yes           | yes            | yes           | no            |
 | pdo                                                        | yes           | yes            | yes           | yes           |

docs/zh/guide/extension-notes.md

@@ -131,3 +131,7 @@ xhprof 扩展包含三部分：`xhprof_extension`、`xhprof_html`、`xhprof_libs
 event 扩展在 macOS 系统下编译后暂无法使用 `openpty` 特性。相关 Issue：
 
 - [static-php-cli#335](https://github.com/crazywhalecc/static-php-cli/issues/335)
+
+## parallel
+
+parallel 扩展只支持 PHP 8.0 及以上版本，并只支持 ZTS 构建（`--enable-zts`）。