Make MariaDB a dependency so that users only have to install a single Helm chart

[blu3r4y]

Is your feature request related to a problem? Please describe.
I believe we can easily reduce the complexity of the quickstart guide by making MariaDB a dependency that is automatically installed with the Unguard Helm chart, instead of asking the user to manually do it.

Describe the solution you'd like
AFAIK Helm allows to specify dependencies in Chart.yaml where we could easily reference the MariaDB Helm chart.
See https://helm.sh/docs/helm/helm_dependency/ for more details.

This would allow users to install Unguard with a single helm install command.

Describe alternatives you've considered
None.

Additional context
I would need to briefly reference "how to install Unguard" in another document. Saying "hey, just do a helm install unguard" is easier and easily understood instead of saying "well, first, you need mariadb, then, you can install this helm chart ..."