lint: fix all major issues

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

config/default.go

@@ -53,6 +53,7 @@ func (c *defaultConfig) Load(ctx context.Context) error {
 	return nil
 }
 
+//nolint:gocyclo
 func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val string) error {
 	if !rutil.IsEmpty(value) {
 		return nil

config/options.go

@@ -121,7 +121,7 @@ func Struct(v interface{}) Option {
 	}
 }
 
-// StructTag
+// StructTag sets the struct tag that used for filling
 func StructTag(name string) Option {
 	return func(o *Options) {
 		o.StructTag = name