Update docs/installing-mise.md

Co-authored-by: Mark Lee <[email protected]>

docs/installing-mise.md

@@ -389,7 +389,7 @@ Then, run the following commands to install the completion script for your shell
 ```sh [bash]
 # This requires bash-completion to be installed
 mkdir -p /etc/bash_completion.d/
-sudo bash -c "mise completion bash --include-bash-completion-lib > /etc/bash_completion.d/mise"
+mise completion bash --include-bash-completion-lib | sudo tee /etc/bash_completion.d/mise > /dev/null
 ```
 
 ```sh [zsh]