docs: fix README to enable copy and use as is

Author: kuredev

README.md

@@ -57,7 +57,7 @@ echo 'export PATH="$HOME/.tfenv/bin:$PATH"' >> ~/.bash_profile
 
 zsh:
 ```console
-$ echo 'export PATH="$HOME/.tfenv/bin:$PATH"' >> ~/.zprofile
+echo 'export PATH="$HOME/.tfenv/bin:$PATH"' >> ~/.zprofile
 ```
 
 fish: