Add option to change default sound

[kroeade]

It's possible to add an option to change the default sound.
There are the changes done in the main.go file, leaving the default tone to the default "pushover":

diff --git a/main.go b/main.go
index a4cd30b..4ac7f7b 100644
--- a/main.go
+++ b/main.go
@@ -17,6 +17,7 @@ const (
        pushoverUserKey  = "pushoverUserKey"
        messageBody      = "messageBody"
        messageTitle     = "messageTitle"
+       messageSound     = "messageSound"
        okPriority       = "okPriority"
        warningPriority  = "warningPriority"
        criticalPriority = "criticalPriority"
@@ -31,6 +32,7 @@ type HandlerConfig struct {
        PushoverUserKey      string
        MessageBodyTemplate  string
        MessageTitleTemplate string
+       MessageSound         string
        OkPriority           uint64
        WarningPriority      uint64
        CriticalPriority     uint64
@@ -82,6 +84,14 @@ var (
                        Usage:     "The message body, in token substitution format",
                        Value:     &config.MessageBodyTemplate,
                },
+               {
+                       Path:      messageSound,
+                       Argument:  messageSound,
+                       Shorthand: "s",
+                       Default:   "pushover",
+                       Usage:     "The sound of the message",
+                       Value:     &config.MessageSound,
+               },
                {
                        Path:      okPriority,
                        Argument:  okPriority,
@@ -181,6 +191,7 @@ func SendPushover(event *corev2.Event) error {
        pushoverForm.Add("token", config.PushoverToken)
        pushoverForm.Add("user", config.PushoverUserKey)
        pushoverForm.Add("priority", priority)
+       pushoverForm.Add("sound", config.MessageSound)
        pushoverForm.Add("title", messageTitle)
        pushoverForm.Add("message", messageBody)

[nixwiz]

Thanks @kroeade , I'll look at getting this added in today or tomorrow1