* fix config.m4

+ add to README.md unix build

Author: EdmondDantes

README.md

@@ -34,30 +34,50 @@ PHP TRUE ASYNC is supported for PHP 8.5.0 and later.
 
 ### Unix / macOS
 
-1. **Clone the repository:**
+1. **Clone the PHP repository:**
+
+    for example, basic directory name is `php-src`:
 
    ```
-   git clone https://github.com/true-async/php-src -b true-async-api
-   cd php-src/ext/async
+   git clone https://github.com/true-async/php-src -b true-async-api ./php-src
    ```
 
-2. **Prepare the build environment:**
+2. **Clone the `True Async` extension repository:**
 
-   ```
-   phpize
-   ```
+    to the `ext` directory of your PHP source:
+
+    ```
+    git clone https://github.com/true-async/php-async ./php-src/ext/async
+    ```
 
-3. **Install LibUV:**:
+3. **Install PHP development tools:**
+
+    Make sure you have the necessary development tools installed. On Debian/Ubuntu, you can run:
+    
+    ```
+    sudo apt-get install php-dev build-essential autoconf libtool pkg-config
+    ```
+    
+    For macOS, you can use Homebrew:
+    
+    ```
+    brew install autoconf automake libtool pkg-config
+    ```
+
+4. **Install LibUV:**:
    
 Please see the [LibUV installation guide](https://github.com/libuv/libuv)
 
-4. **Configure and build:**
+5. **Configure and build:**
 
    ```
+   ./buildconf
    ./configure --enable-experimental-async-api --enable-async
    make && sudo make install
    ```
 
+   We can use `--enable-debug` to enable debug mode, which is useful for development.
+
 ---
 
 ### Windows
@@ -79,7 +99,7 @@ Please see the [LibUV installation guide](https://github.com/libuv/libuv)
 4. **Configure and build the extension with PHP:**
 
    ```
-   cd \path\to\php-src\ext\async
+   cd \path\to\php-src
    buildconf
    configure --enable-experimental-async-api --enable-async
    nmake

config.m4

@@ -10,7 +10,7 @@ PHP_ARG_WITH([async_libuv],
 
 if test "$PHP_ASYNC" = "yes"; then
 
-  if test "$PHP_ASYNC_API" != "yes"; then
+  if test "$PHP_ASYNC_API" != "yes" && test "$PHP_EXPERIMENTAL_ASYNC_API" != "yes"; then
     AC_MSG_ERROR([PHP TRUE ASYNC API is required. Please configure PHP with --enable-experimental-async-api])
   fi