open url based on OS

lua/telescope/_extensions/getOS.lua

@@ -0,0 +1,10 @@
+return function()
+    -- ask LuaJIT first
+    if jit then return jit.os end
+
+    -- Unix, Linux variants
+    local fh, _ = assert(io.popen('uname -o 2>/dev/null', 'r'))
+    if fh then return fh:read() end
+
+    return 'Windows'
+end