Add Docker setup

.docker/php81.Dockerfile

@@ -0,0 +1,6 @@
+FROM php:8.1-cli
+
+RUN apt-get update && \
+    apt-get install -y unzip
+
+COPY --from=composer:latest /usr/bin/composer /usr/local/bin/composer

.docker/php82.Dockerfile

@@ -0,0 +1,6 @@
+FROM php:8.2-cli
+
+RUN apt-get update && \
+    apt-get install -y unzip
+
+COPY --from=composer:latest /usr/bin/composer /usr/local/bin/composer

.docker/php83.Dockerfile

@@ -0,0 +1,6 @@
+FROM php:8.3-cli
+
+RUN apt-get update && \
+    apt-get install -y unzip
+
+COPY --from=composer:latest /usr/bin/composer /usr/local/bin/composer

.gitattributes

@@ -1,7 +1,9 @@
-/.github           export-ignore
-/tests             export-ignore
-.gitattributes     export-ignore
-.gitignore         export-ignore
-.scrutinizer.yml   export-ignore
-phpstan.neon.dist  export-ignore
-phpunit.xml.dist   export-ignore
+/.docker            export-ignore
+/.github            export-ignore
+/tests              export-ignore
+.gitattributes      export-ignore
+.gitignore          export-ignore
+.scrutinizer.yml    export-ignore
+docker-compose.yml  export-ignore
+phpstan.neon.dist   export-ignore
+phpunit.xml.dist    export-ignore

docker-compose.yml

@@ -0,0 +1,24 @@
+version: '3.8'
+
+services:
+  php81:
+    build:
+      context: .
+      dockerfile: .docker/php81.Dockerfile
+    working_dir: /var/www/html
+    volumes:
+      - .:/var/www/html:delegated
+  php82:
+    build:
+      context: .
+      dockerfile: .docker/php82.Dockerfile
+    working_dir: /var/www/html
+    volumes:
+      - .:/var/www/html:delegated
+  php83:
+    build:
+      context: .
+      dockerfile: .docker/php83.Dockerfile
+    working_dir: /var/www/html
+    volumes:
+      - .:/var/www/html:delegated