update documentation for fahnerit_web\StyleService

C. Fahner <info@fahnerit.com>
remove KeyValueStore dependency

C. Fahner <info@fahnerit.com>
remove fahnerit_web\WebSettings

C. Fahner <info@fahnerit.com>
fix old wrong SettingsService reference
small docs modification

C. Fahner <info@fahnerit.com>