Update docs

Author: petk

docs/configuration.md

@@ -165,12 +165,6 @@ documentation.
 
 ## 3. PHP configuration
 
-* `PHP_RE2C_CGOTO=OFF|ON`
-
-  Default: `OFF`
-
-  Enable the goto C statements when using re2c.
-
 * `PHP_BUILD_ARCH`
 
   Default: `${CMAKE_SYSTEM_PROCESSOR}`
@@ -189,14 +183,6 @@ documentation.
 
   Build provider displayed in phpinfo.
 
-* `SED_EXECUTABLE`
-
-  Default path to the sed on the host system.
-
-  Path to the sed, which can be manually overridden to the sed on the target
-  system. This is only used in generated phpize (and php-config) scripts on *nix
-  systems.
-
 * `PHP_CCACHE=ON|OFF`
 
   Default: `ON`
@@ -206,6 +192,27 @@ documentation.
   option or by setting environment variable `CCACHE_DISABLE=1`. A custom path to
   the `ccache` installation directory can be also set with the `Ccache_ROOT`.
 
+* `PHP_INCLUDE_PREFIX`
+
+  Default: `php`
+
+  Relative directory inside the `CMAKE_INSTALL_INCLUDEDIR` to adjust installed
+  headers location. For example, to specify PHP version: `php/8.4` or similar.
+
+* `PHP_RE2C_CGOTO=OFF|ON`
+
+  Default: `OFF`
+
+  Enable the goto C statements when using re2c.
+
+* `SED_EXECUTABLE`
+
+  Default path to the sed on the host system.
+
+  Path to the sed, which can be manually overridden to the sed on the target
+  system. This is only used in generated phpize (and php-config) scripts on *nix
+  systems.
+
 ## 4. Zend engine configuration
 
 ## 5. PHP SAPI modules configuration

docs/php-installation.md

@@ -222,6 +222,21 @@ These variables are by default relative paths. When customized, they can be
 either relative or absolute. When changed to absolute values the installation
 prefix will not be taken into account.
 
+> [!TIP]
+> To set the PHP include directory, there is also `PHP_INCLUDE_PREFIX` cache
+> variable available, that can adjust the path inside the
+> `CMAKE_INSTALL_INCLUDEDIR`.
+>
+> ```sh
+> <CMAKE_INSTALL_PREFIX>          # /usr/local
+> └─ <CMAKE_INSTALL_INCLUDEDIR>   # └─ include
+>    └─ <PHP_INSTALL_PREFIX>      #    └─ php
+>       ├─ ext                    #       ├─ ext
+>       ├─ main                   #       ├─ main
+>       ├─ sapi                   #       ├─ sapi
+>       ├─ TSRM                   #       ├─ TSRM
+>       └─ Zend                   #       └─ Zend
+
 Instead of setting the installation prefix at the configuration phase using
 `CMAKE_INSTALL_PREFIX` variable or `--install-prefix` option, there is
 also `installDir` field which can be set in the `CMakePresets.json` or