Use roles native files directory to store the custom theme

roles/keycloak/theme/archlinux/account/index.ftl

.../archlinux/account/resources/public/archlinux-favicon.ico

...rchlinux/account/resources/public/archlinux-logo-dark.svg

...chlinux/account/resources/public/archlinux-logo-light.svg

...cloak/theme/archlinux/account/resources/public/layout.css

roles/keycloak/theme/archlinux/account/theme.properties

...s/keycloak/theme/archlinux/admin/resources/css/custom.css

...me/archlinux/admin/resources/img/archlinux-logo-light.svg

roles/keycloak/theme/archlinux/admin/theme.properties

...s/keycloak/theme/archlinux/login/resources/css/custom.css

...me/archlinux/login/resources/img/archlinux-logo-light.svg

.../theme/archlinux/login/resources/img/login-background.jpg

roles/keycloak/theme/archlinux/login/theme.properties

roles/keycloak/theme/archlinux/welcome/index.ftl

...heme/archlinux/welcome/resources/archlinux-logo-light.svg

...keycloak/theme/archlinux/welcome/resources/css/custom.css

.../theme/archlinux/welcome/resources/welcome-background.jpg

roles/keycloak/theme/archlinux/welcome/theme.properties