Update README.md

Author: simonhamp

README.md

@@ -4,20 +4,38 @@
 
 You can install the package via Composer:
 
-```bash
+```shell
 composer require nativephp/php-bin --dev
 ```
 
 or NPM:
 
-```bash
+```shell
 npm -i @nativephp/php-bin --save-dev
 ```
 
 ### ℹ️ Heads up...
 > You should install this package as a `dev` dependency, in most cases, and simply copy what you need from it to the
 relevant parts of your application. This will save you distributing all of the PHP binaries with every installation.
 
+## Creating new binaries
+
+NativePHP uses [`static-php-cli`](https://static-php.dev) to build minimal, statically-linked, self-contained PHP
+executables for each platform.
+
+The default build commands are:
+
+```shell
+bin/spc download --clear
+bin/spc download --with-php=8.2 --for-extensions "bcmath,ctype,curl,dom,fileinfo,filter,mbstring,openssl,pdo,pdo_sqlite,session,simplexml,sqlite3,tokenizer,xml,zlib"
+```
+
+```shell
+bin/spc build --build-cli --build-embed "bcmath,ctype,curl,dom,fileinfo,filter,mbstring,openssl,pdo,pdo_sqlite,session,simplexml,sqlite3,tokenizer,xml,zlib"
+```
+
+You need to build these on the relevant platform to compile binaries for that platform.
+
 ## Issues
 
 Please raise any issues on the [NativePHP/laravel](/nativephp/laravel/issues/new/choose) repo.