Add categories to readme-vars.yml

Author: quietsy

readme-vars.yml

@@ -6,6 +6,7 @@ project_url: "https://mariadb.org/"
 project_logo: "https://raw.githubusercontent.com/linuxserver/docker-templates/master/linuxserver.io/img/mariadb-git.png"
 project_blurb: "[{{ project_name|capitalize }}]({{ project_url }}) is one of the most popular database servers. Made by the original developers of MySQL."
 project_lsio_github_repo_url: "https://github.com/linuxserver/docker-{{ project_name }}"
+project_categories: "Databases"
 # supported architectures
 available_architectures:
   - {arch: "{{ arch_x86_64 }}", tag: "amd64-latest"}