docs: add MacPorts install instructions

https://ports.macports.org/port/repgrep/

README.md

@@ -77,6 +77,16 @@ from the official repositories using [Pacman](https://wiki.archlinux.org/title/P
 pacman -S repgrep
 ```
 
+#### Via MacPorts (macOS)
+
+`repgrep` can also be installed on macOS using [MacPorts](https://www.macports.org):
+
+```bash
+sudo port install repgrep
+```
+
+More info [here](https://ports.macports.org/port/repgrep/).
+
 #### From Source (via Cargo)
 
 **NOTE**: The minimum Rust version required is `1.65.0`.
@@ -91,4 +101,4 @@ cargo install --path .
 [releases]: https://github.com/acheronfail/repgrep/releases
 [`ripgrep` installation instructions]: https://github.com/BurntSushi/ripgrep/#installation
 
-License: Unlicense OR MIT OR Apache-2.0
+License: Unlicense OR MIT OR Apache-2.0