Improve macOS doc (#173)

* Use "macOS" instead of "Mac OS"
* List various possible installation directories

Co-authored-by: Romain Failliot <[email protected]>

Author: krlmlr

docs/developers/developers-setup.md

@@ -37,7 +37,7 @@ _Note: Tested on Fedora 36_
 </details>
 
 <details>
-    <summary>Mac OS</summary>
+    <summary>macOS</summary>
 
 On Mac, all dependencies can be installed using [Homebrew](https://docs.brew.sh/):
 
@@ -111,7 +111,7 @@ meson test
 To install Diffuse on your system (e.g. `/usr/local/`):
 
 ```sh
-meson install # requires admin privileges
+meson install  # requires admin privileges
 ```
 
 To run Diffuse:
@@ -148,11 +148,12 @@ sudo ninja uninstall -C build
 sudo rm -v /usr/local/share/locale/*/LC_MESSAGES/diffuse.mo
 ```
 
-### Setup on Mac OS
+### Setup on macOS
 
 #### Build and test
 
-Diffuse is using Meson as its build system.
+Diffuse is using Meson as its build system, this is the only supported system
+on macOS.
 
 To build and test Diffuse:
 
@@ -165,10 +166,11 @@ meson test
 
 #### Install on system and run
 
-To install Diffuse on your system (e.g. `/usr/local/`):
+To install Diffuse on your system (e.g. `/Applications/` and `/opt/homebrew/`
+or `/usr/local/`):
 
 ```sh
-meson install # requires admin privileges
+meson install  # requires admin privileges
 ```
 
 To run Diffuse: