- move the initialization of config/library/storage to mango.cr

- remove duplicate initialization of server in server.cr

src/config.cr

@@ -14,6 +14,9 @@ class Config
 	@[YAML::Field(key: "db_path")]
 	property db_path = File.expand_path "~/mango/mango.db", home: true
 
+	@[YAML::Field(key: "scan_interval_minutes")]
+	property scan_interval = 5
+
 	def self.load
 		cfg_path = File.expand_path "~/.config/mango/config.yml", home: true
 		if File.exists? cfg_path