Implement YAML config loader

Dockerfile

@@ -3,8 +3,10 @@ FROM php:7.4-apache AS base
 WORKDIR /var/www
 
 RUN apt-get update && \
-    apt-get install -y libzip-dev unzip git && \
-    docker-php-ext-install pdo pdo_mysql zip
+    apt-get install -y git unzip libyaml-dev libzip-dev && \
+    docker-php-ext-install pdo pdo_mysql zip && \
+    pecl install yaml && \
+    docker-php-ext-enable yaml
 
 RUN a2enmod rewrite && \
     sed -ri -e 's!/var/www/html!/var/www/public!g' /etc/apache2/sites-available/*.conf