Build Command implementation

[asgrim]

Fixes #3

I'm going to merge this one fairly soon, as it isn't a huge add. Assuming there is no show-stoppers, I'll probably merge end of this week, or beginning of next, just in case anyone wants to give any further feedback.

Are you an end user who would like to try this out?

Please note that this is just an initial implementation, and will only download and build an extension to a temporary path on your machine; it will not install anything just yet. That is coming soon!

If you understand, and you'd still like to help test this...

Primarily the best way to provide feedback here as an end user of PIE is to check the build command works on your machine! You can do that by following these steps (please adjust for your platform differences of course!)

• Ensure you are using PHP 8.3 (this is because my test extension asgrim/example-pie-extension is intentionally only compatible with PHP 8.3)
• git clone -b download-implementation https://github.com/asgrim/pie.git
• composer install
• bin/pie build asgrim/example-pie-extension
• Let me know if you encounter any errors or something unexpected!

You should see something like:

$ bin/pie build asgrim/example-pie-extension
You are running PHP 8.3.8
Target PHP installation: 8.3.8 nts, on Linux/OSX/etc x86_64 (from /usr/bin/php8.3)
Found package: asgrim/example-pie-extension:1.0.1 which provides ext-example_pie_extension
phpize complete.
Configure complete.
Build complete.

Are you an extension maintainer who would like to try this out?

It's not strictly necessary to support this just yet, but if you're keen, and please note, things may change before we finally release PIE... so you do this at your own risk. Note: at the moment, you will need to make a new release - see ThePHPF/pie-design#17

• Add and commit a composer.json to your repo - example here https://github.com/asgrim/example-pie-extension/blob/main/composer.json
• Make a release (alpha release is fine, e.g. 1.2.3-alpha.) - note, "branches" or "commits" are not yet supported - see Add support for dev-main and dev-main#sha type version requests #13
• Then, add it to Packagist here: https://packagist.org/packages/submit (you put the GH URL in, it should detect the composer.json automatically and understand that it is a php-ext or php-ext-zend, it should appear in https://packagist.org/extensions once added

More details, for example for help on composer.json, can be read in https://github.com/ThePHPF/pie-design?tab=readme-ov-file#extension-maintainer-register-a-pie-package