doc: add note to readme about backward compatibility

README.md

@@ -101,6 +101,7 @@ If you need to use Tabnine on Windows and Unix you can change the config as foll
 ```lua
 -- Get platform dependant build script
 local function tabnine_build_path()
+  -- Replace vim.uv with vim.loop if using NVIM 0.9.0 or below
   if vim.uv.os_uname().sysname == "Windows_NT" then
     return "pwsh.exe -file .\\dl_binaries.ps1"
   else