feat: add --github-badge flag to core options (#502)

## What type of PR is this?

/kind feature

## What this PR does / why we need it:

Add `--github-badge` flag to core options.

## Which issue(s) this PR fixes:

Prepare for #501

cmd/app/options/core_options.go

@@ -21,6 +21,7 @@ import (
 
 type CoreOptions struct {
 	ReadOnlyMode bool
+	GithubBadge  bool
 }
 
 func NewCoreOptions() *CoreOptions {
@@ -33,6 +34,7 @@ func (o *CoreOptions) Validate() []error {
 
 func (o *CoreOptions) ApplyTo(config *registry.ExtraConfig) error {
 	config.ReadOnlyMode = o.ReadOnlyMode
+	config.GithubBadge = o.GithubBadge
 	return nil
 }
 
@@ -43,4 +45,5 @@ func (o *CoreOptions) AddFlags(fs *pflag.FlagSet) {
 	}
 
 	fs.BoolVar(&o.ReadOnlyMode, "read-only-mode", false, "turn on the read only mode")
+	fs.BoolVar(&o.GithubBadge, "github-badge", false, "whether to display the github badge")
 }

pkg/kubernetes/registry/types.go

@@ -36,4 +36,5 @@ type ExtraConfig struct {
 	ElasticSearchUsername  string
 	ElasticSearchPassword  string
 	ReadOnlyMode           bool
+	GithubBadge            bool
 }