use clipboard package to handle clipboard stuff

pkg/config/config_default_platform.go

@@ -7,6 +7,5 @@ func GetPlatformDefaultConfig() []byte {
 	return []byte(
 		`os:
   openCommand: 'open {{filename}}'
-  openLinkCommand: 'open {{link}}'
-  copyToClipboardCommand: 'bash -c "echo -n {{str}} | pbcopy"'`)
+  openLinkCommand: 'open {{link}}'`)
 }