update macOS launchd example (#1600)

* update to match same paths as systemd

* update to match new launchd plist

* generated from scratch with LaunchControl, flawless

Had some issues with the previous go and found LaunchControl which made it easy to generate a perfectly correct launchd conf

* Update README.md

dist/init/mac-launchd/README.md

 launchd service for macOS
 =========================
 
-This is a sample file for a *launchd* service on Mac.
-Edit the paths and email in the plist file to match your info.
+This is a working sample file for a *launchd* service on Mac, which should be placed here:
+
+```bash
+/Library/LaunchDaemons/com.caddyserver.web.plist
+```
+
+To create the proper directories as used in the example file:
+
+```bash
+sudo mkdir -p /etc/caddy /etc/ssl/caddy /var/log/caddy /usr/local/bin /var/tmp /srv/www/localhost
+sudo touch /etc/caddy/Caddyfile
+sudo chown root:wheel -R /usr/local/bin/caddy /Library/LaunchDaemons/
+sudo chown _www:_www -R /etc/caddy /etc/ssl/caddy /var/log/caddy
+sudo chmod 0750 /etc/ssl/caddy
+```
+
+Create a simple web page and Caddyfile
+
+```bash
+sudo bash -c 'echo "Hello, World!" > /srv/www/localhost/index.html'
+sudo bash -c 'echo "http://localhost {
+    root /srv/www/localhost
+}" >> /etc/caddy/Caddyfile'
+```
 
 Start and Stop the Caddy launchd service using the following commands:
 
-    $ launchctl load ~/Library/LaunchAgents/com.caddyserver.web.plist
-    $ launchctl unload ~/Library/LaunchAgents/com.caddyserver.web.plist
+```bash
+launchctl load /Library/LaunchDaemons/com.caddyserver.web.plist
+launchctl unload /Library/LaunchDaemons/com.caddyserver.web.plist
+```
+
+To start on every boot use the `-w` flag (to write):
+
+```bash
+launchctl load -w /Library/LaunchAgents/com.caddyserver.web.plist
+```
 
-More information can be found in this blogpost: [Running Caddy as a service on macOS X server](https://denbeke.be/blog/software/running-caddy-as-a-service-on-macos-os-x-server/)
\ No newline at end of file
+More information can be found in this blogpost: [Running Caddy as a service on macOS X server](https://denbeke.be/blog/software/running-caddy-as-a-service-on-macos-os-x-server/)

dist/init/mac-launchd/com.caddyserver.web.plist

 <?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
-    <dict>
-        <key>Label</key>
-        <string>com.caddyserver.web</string>
-        <key>EnvironmentVariables</key>
-        <dict>
-            <key>HOME</key>
-            <string>/Users/mathias</string>
-        </dict>
-        <key>ProgramArguments</key>
-        <array>
-            <string>sh</string>
-            <string>-c</string>
-            <string>ulimit -n 8192; cd /Users/mathias/Sites; ./caddy -agree -email my_email@domain.com -conf=/Users/mathias/Sites/Caddyfile</string>
-        </array>
-        <key>UserName</key>
-        <string>www</string>
-        <key>RunAtLoad</key>
-        <true/>
-        <key>KeepAlive</key>
-        <true/>
-        <key>WorkingDirectory</key>
-        <string>/Users/mathias/Sites</string>
-        <key>StandardOutPath</key>
-        <string>/Users/mathias/Sites/caddy.log</string>
-        <key>StandardErrorPath</key>
-        <string>/Users/mathias/Sites/caddy_error.log</string>
-    </dict>
-</plist>
\ No newline at end of file
+<dict>
+	<key>Label</key>
+	<string>Caddy</string>
+	<key>ProgramArguments</key>
+	<array>
+		<string>/usr/local/bin/caddy</string>
+		<string>-agree</string>
+		<string>-conf</string>
+		<string>/etc/caddy/Caddyfile</string>
+		<string>-root</string>
+		<string>/var/tmp</string>
+	</array>
+	<key>EnvironmentVariables</key>
+	<dict>
+		<key>CADDYPATH</key>
+		<string>/etc/ssl/caddy</string>
+	</dict>
+
+	<key>UserName</key>
+	<string>root</string>
+	<key>GroupName</key>
+	<string>wheel</string>
+	<key>InitGroups</key>
+	<true/>
+
+	<key>RunAtLoad</key>
+	<true/>
+	<key>KeepAlive</key>
+	<dict>
+		<key>Crashed</key>
+		<true/>
+	</dict>
+
+	<key>SoftResourceLimits</key>
+	<dict>
+		<key>NumberOfFiles</key>
+		<integer>8192</integer>
+	</dict>
+	<key>HardResourceLimits</key>
+	<dict/>
+
+	<key>WorkingDirectory</key>
+	<string>/etc/ssl/caddy</string>
+
+	<key>StandardErrorPath</key>
+	<string>/var/log/caddy/error.log</string>
+	<key>StandardOutPath</key>
+	<string>/var/log/caddy/info.log</string>
+</dict>
+</plist>