Add a GetConfig method (#387)

* Update rule.go

* fix: fix lint and add GetConfig to interface

Author: hugo-syn

rule.go

@@ -90,6 +90,11 @@ func (r *RuleBase) SetConfig(cfg *Config) {
 	r.config = cfg
 }
 
+// GetConfig returns the config of the rule
+func (r *RuleBase) GetConfig() *Config {
+	return r.config
+}
+
 // Rule is an interface which all rule structs must meet.
 type Rule interface {
 	Pass
@@ -98,4 +103,5 @@ type Rule interface {
 	Description() string
 	EnableDebug(out io.Writer)
 	SetConfig(cfg *Config)
+	GetConfig() *Config
 }