feat(detect-os.lua): add script to detect the operating system and return

the corresponding value based on the environment variables and system
commands available

lua/absolute/utils/detect-os.lua

@@ -0,0 +1,43 @@
+SUPPORTED_OS = {
+    WINDOWS = "Windows",
+    UNIX = "Unix",
+    MACOS = "macOS",
+}
+
+local function isMacOS()
+    -- Try to execute `sw_vers` command which is specific to macOS
+    local result = os.execute("sw_vers > /dev/null 2>&1")
+
+    -- `os.execute` returns true on success for Lua versions 5.2 and above
+    -- For Lua 5.1 and below, it returns the exit code of the command. On success, it should be zero.
+    -- Adjust the check if you're using Lua 5.1 or below:
+    -- if result == 0 then
+    if result then
+        return true
+    else
+        return false
+    end
+end
+
+local function detectOS()
+    if os.getenv("OS") ~= nil then
+        return os.getenv("OS") -- This can be useful in Windows environments
+    elseif os.getenv("PATH"):find(";") then
+        return SUPPORTED_OS.WINDOWS
+    else
+        local is_macos = isMacOS()
+
+        if is_macos then
+            return SUPPORTED_OS.MACOS
+        else
+            return SUPPORTED_OS.UNIX
+        end
+    end
+end
+
+M = {}
+
+M.detect = detectOS
+M.supported = SUPPORTED_OS
+
+return M