feat: Build image with new PHP 8.1 version (#29)

Author: shrink

README.md

@@ -2,18 +2,18 @@
 
 Docker Image for PHP API applications.
 
-**Alpine** [`3.13`][alpine-3.13] + **nginx** [`1.18`][nginx-1.18] +
-**PHP** [`8.0`][php-8.0]
+**Alpine** [`3.15`][alpine] + **nginx** [`1.20`][nginx] +
+**PHP** [`8.1`][php]
 
 ```dockerfile
 FROM ghcr.io/shrink/docker-php-api:8
 ```
 
-* **All** requests are routed to `public/index.php`
-* `xml` and `json` responses are gzipped
-* nginx runs on port `8080`
-* PHP-FPM status is exposed via `/.container/status` and `/.container/ping`
-* Available for [PHP 7 ↓](#php-versions)
+- **All** requests are routed to `public/index.php`
+- `xml` and `json` responses are gzipped
+- nginx runs on port `8080`
+- PHP-FPM status is exposed via `/.container/status` and `/.container/ping`
+- Available for [PHP 7 ↓](#php-versions)
 
 See an example usage in
 [Laravel Strict `shrink/laravel-strict`][shrink/laravel-strict].
@@ -31,7 +31,7 @@ Most production use-cases are best served by
 digest to guarantee reproducibility, e.g:
 
 ```dockerfile
-FROM ghcr.io/shrink/docker-php-api@sha256:637a6ff82d27001b8137e807f6da49d2a8c6d1e234e757945454069ebdec0720
+FROM ghcr.io/shrink/docker-php-api@sha256:7ea108539c53d2e601b17c23d9f3b0aacd627c3873eb1ef52187dd71a41ba061
 ```
 
 ## PHP Versions
@@ -43,19 +43,21 @@ major and minor version (e.g: `7` and `7.4`).
 FROM ghcr.io/shrink/docker-php-api:7
 ```
 
-A full list of available image versions can be found in
-the [GitHub Container Registry][ghcr/shrink/docker-php-api].
+[`images.json`][images-manifest] is the manifest describing the images to be
+built by the CI. The [GitHub Container Registry][ghcr/shrink/docker-php-api]
+contains a full list of all built images with their tags and digests.
 
 ## Credits
 
 Optimized PHP-FPM configuration based on
-[TrafeX/docker-php-nginx][TrafeX/docker-php-nginx].
+[TrafeX/docker-php-nginx][trafex/docker-php-nginx].
 
-[TrafeX/docker-php-nginx]: https://github.com/TrafeX/docker-php-nginx
-[alpine-3.13]: https://alpinelinux.org/posts/Alpine-3.13.0-released.html
-[nginx-1.18]: http://nginx.org/en/CHANGES-1.18
-[php-8.0]: https://www.php.net/ChangeLog-8.php#PHP_8_0
+[trafex/docker-php-nginx]: https://github.com/TrafeX/docker-php-nginx
+[alpine]: https://alpinelinux.org/posts/Alpine-3.15.0-released.html
+[nginx]: http://nginx.org/en/CHANGES-1.20
+[php]: https://www.php.net/ChangeLog-8.php#PHP_8_1
 [shrink/laravel-strict]: https://github.com/shrink/laravel-strict
 [docker-digest-pinning]: https://docs.docker.com/engine/reference/commandline/pull/#pull-an-image-by-digest-immutable-identifier
 [ghcr/shrink/docker-php-api]: https://github.com/users/shrink/packages/container/package/docker-php-api
 [php/supported-versions]: https://www.php.net/supported-versions.php
+[images-manifest]: /images.json

images.json

@@ -1,4 +1,10 @@
 [
+  {
+    "tag": "8.1",
+    "php": "8.1",
+    "alpine": "3.15",
+    "nginx": "~1.20"
+  },
   {
     "tag": "8.0",
     "php": "8.0",