UI: Add Restream.io link to stream key page

Allows the users to find their stream key via a specified link if they
opt to just use a stream key instead of integration.

UI/window-basic-auto-config.cpp

@@ -575,6 +575,13 @@ void AutoConfigStreamPage::UpdateKeyLink()
 		text += "</a>";
 
 		isYoutube = true;
+	} else if (serviceName.startsWith("Restream.io")) {
+		text += " <a href=\"https://";
+		text += "restream.io/settings/streaming-setup?from=OBS";
+		text += "\">";
+		text += QTStr(
+			"Basic.AutoConfig.StreamPage.StreamKey.LinkToSite");
+		text += "</a>";
 	}
 
 	if (isYoutube) {

UI/window-basic-settings-stream.cpp

@@ -198,6 +198,13 @@ void OBSBasicSettings::UpdateKeyLink()
 		text += QTStr(
 			"Basic.AutoConfig.StreamPage.StreamKey.LinkToSite");
 		text += "</a>";
+	} else if (serviceName.startsWith("Restream.io")) {
+		text += " <a href=\"https://";
+		text += "restream.io/settings/streaming-setup?from=OBS";
+		text += "\">";
+		text += QTStr(
+			"Basic.AutoConfig.StreamPage.StreamKey.LinkToSite");
+		text += "</a>";
 	}
 
 	ui->streamKeyLabel->setText(text);