MM-12193: illustrate simplified, but safe configuration handling

server/plugin.go

@@ -1,11 +1,20 @@
 package main
 
 import (
+	"sync"
+
 	"github.com/mattermost/mattermost-server/plugin"
 )
 
 type Plugin struct {
 	plugin.MattermostPlugin
+
+	// configurationLock synchronizes access to the configuration.
+	configurationLock sync.RWMutex
+
+	// configuration is the active plugin configuration. Consult getConfiguration and
+	// setConfiguration for usage.
+	configuration *configuration
 }
 
 // See https://developers.mattermost.com/extend/plugins/server/reference/