add install instructions for mac (#49)

Support/INSTALL_mac.md

@@ -0,0 +1,32 @@
+# Installation
+
+## Dependencies
+
+[Homebrew](https://brew.sh/)
+
+```bash
+brew install wine
+brew install mingw-w64
+```
+
+## Building
+
+```bash
+git clone https://github.com/galaxyhaxz/devilution
+cd devilution
+cp /path/to/diablo_game_dir/diabloui.dll .
+cp /path/to/diablo_game_dir/Storm.dll .
+make
+```
+
+## Install
+
+```bash
+cp devilution.exe /path/to/diablo_game_dir/
+```
+
+## Run
+
+```bash
+wine devilution.exe
+```