(docs): update org-protocol installation for MacOS (#225)

doc/roam_protocol.md

@@ -95,8 +95,7 @@ policy.
 
 ## Mac OS
 
-One solution to this, recommended in [Issue
-#115](https://github.com/jethrokuan/org-roam/issues/115), is to use
+One solution is to use
 [Platypus](https://github.com/sveinbjornt/Platypus). Here are the
 instructions for setting up with Platypus and Chrome:
 
@@ -105,17 +104,24 @@ instructions for setting up with Platypus and Chrome:
 ```sh
 brew cask install playtpus
 ```
+2. Create a script `launch_emacs.sh`:
 
-2. Platypus settings:
+```
+#!/usr/bin/env bash
+/usr/local/bin/emacsclient --no-wait $1
+```
+
+2. Create a Platypus app with the following settings:
+
+| Setting                        | Value                     |
+|--------------------------------+---------------------------|
+| App Name                       | "OrgProtocol"             |
+| Script Type                    | "env" · "/usr/bin/env"    |
+| Script Path                    | "path/to/launch-emacs.sh" |
+| Interface                      | None                      |
+| Accept dropped items           | true                      |
+| Remain running after execution | false                     |
 
-- App Name: `OrgProtocol`
-- Script Type: `env` and `/usr/bin/env`
-- Script Path: `/path/to/emacsclient $1`
-- Tick Accept dropped items and click Settings
-- Tick Accept dropped files
-- Tick Register as URI scheme handler
-- Add `org-protocol` as a protocol
-- Create the app
 
 To disable the "confirm" prompt in Chrome, you can also make Chrome
 show a checkbox to tick, so that the `OrgProtocol` app will be used
@@ -125,4 +131,20 @@ without confirmation. To do this, run in a shell:
 defaults write com.google.Chrome ExternalProtocolDialogShowAlwaysOpenCheckbox -bool true
 ```
 
+
+##### Note for Emacs Mac Port
+
+If you're using [Emacs Mac Port](https://github.com/railwaycat/homebrew-emacsmacport), it
+registered its `Emacs.app` as the default handler for the URL scheme
+`org-protocol`. We have to make our `OrgProtocol.app` the default
+handler instead (replace `org.yourusername.OrgProtocol` with your app
+identifier):
+
+```
+$ defaults write com.apple.LaunchServices/com.apple.launchservices.secure LSHandlers -array-add \
+'{"LSHandlerPreferredVersions" = { "LSHandlerRoleAll" = "-"; }; LSHandlerRoleAll = "org.yourusername.OrgProtocol"; LSHandlerURLScheme = "org-protocol";}'
+```
+
+Then restart your computer.
+
 [org-protocol-inst]: https://orgmode.org/worg/org-contrib/org-protocol.html