Add homebrew installation instructions to README.md (#718)

Co-authored-by: Sebastian Ehlert <[email protected]>

Author: rouson

README.md

@@ -101,6 +101,21 @@ For more details check the package information [here](https://spack.readthedocs.
 [Spack]: https://spack.io
 
 
+#### Homebrew
+
+The Fortran Package Manager (fpm) is available for the [homebrew](https://brew.sh/) package manager on MacOS via an additional tap.
+To install fpm via brew, include the new tap and install it using
+
+```
+brew tap fortran-lang/fortran
+brew install fpm
+```
+
+Binary distributions are available for MacOS 11 (Catalina) and 12 (Big Sur) for x86_64 architectures. For other platforms fpm will be built locally from source automatically.
+
+Fpm should be available and functional after those steps.
+For more details checkout the tap [here](https://github.com/fortran-lang/homebrew-fortran).
+
 #### Github Actions
 
 To setup *fpm* within Github actions for automated testing, you can use the [fortran-lang/setup-fpm](https://github.com/marketplace/actions/setup-fpm) action.