README: remove ../local/.. from auto-completion setup command (#181)

Author: CleanMachine1

README.md

@@ -95,8 +95,11 @@ If you are experiencing issues with *tldr*, consider deleting the cache files be
 ```bash
 # bash
 tldr --print-completion bash | sudo tee "$BASH_COMPLETION_COMPAT_DIR"/tldr
-# zsh
+# zsh (it is recommended to check where zsh/site-functions directory is located)
+## for macOS:
 tldr --print-completion zsh | sudo tee /usr/local/share/zsh/site-functions/_tldr
+## for Linux:
+tldr --print-completion zsh | sudo tee /usr/share/zsh/site-functions/_tldr
 ```
 
 See the `shtab` [docs](https://pypi.org/project/shtab/#usage) for other installation methods.