Add beginnings of "previous song" action

For some reason, this action doesn't work. When you trigger the action
in LaunchBar, you can *see* it clicking the "previous song" button in the
Sonos UI, but Sonos doesn't actually go to the previous song. 🤷‍♂️

xref: b551555

sonos-previous-song.lbaction/Contents/Info.plist

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleIconFile</key>
+	<string>previous-song.png</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.jasonrudolph.LaunchBar.action.SonosPreviousSong</string>
+	<key>CFBundleName</key>
+	<string>Sonos - Previous Song</string>
+	<key>CFBundleVersion</key>
+	<string>1.0</string>
+	<key>LBDescription</key>
+	<dict>
+		<key>LBAuthor</key>
+		<string>Jason Rudolph</string>
+		<key>LBRequirements</key>
+		<string>Sonos Controller for Mac v7.1</string>
+		<key>LBSummary</key>
+		<string>Go back to the previous song in the macOS Sonos app</string>
+		<key>LBTwitter</key>
+		<string>@jasonrudolph</string>
+		<key>LBWebsiteURL</key>
+		<string>http://jasonrudolph.com</string>
+	</dict>
+	<key>LBRequiredApplication</key>
+	<string>com.sonos.macController</string>
+	<key>LBRequirements</key>
+	<string>Sonos Controller for Mac v7.1</string>
+	<key>LBScripts</key>
+	<dict>
+		<key>LBDefaultScript</key>
+		<dict>
+			<key>LBScriptName</key>
+			<string>default.scpt</string>
+		</dict>
+	</dict>
+</dict>
+</plist>

sonos-previous-song.lbaction/Contents/Scripts/default.scpt

@@ -0,0 +1,5 @@
+tell application "System Events"
+	tell process "Sonos"
+		click button 2 of window 1
+	end tell
+end tell