Added Add Host Functionality

+added function to add server from tui
+added function to eddit and delete server from tui

internal/config/config.go

@@ -17,4 +17,13 @@ func LoadConfig(path string) (models.AppConfig, error) {
 
 	err = yaml.Unmarshal(data, &cfg)
 	return cfg, err
+}
+
+func SaveConfig(path string, cfg models.AppConfig) error {
+	data, err := yaml.Marshal(&cfg)
+	if err != nil {
+		return err
+	}
+
+	return os.WriteFile(path, data, 0600)
 }