build: add build tags to create customizable binaries

pkg/extensions/config.go

@@ -0,0 +1,16 @@
+package extensions
+
+import "time"
+
+type ExtensionConfig struct {
+	Search *SearchConfig
+}
+
+type SearchConfig struct {
+	// CVE search
+	CVE *CVEConfig
+}
+
+type CVEConfig struct {
+	UpdateInterval time.Duration // should be 2 hours or more, if not specified default be kept as 24 hours
+}