Update bash autocomplete filename

The pre-existing path does not load automatically.

Co-authored-by: Ranjan Purbey <ranjan.purbey@gmail.com>

docs/_index.md

@@ -169,7 +169,7 @@ See `poetry help completions` for full details, but the gist is as simple as usi
 
 ```bash
 # Bash
-poetry completions bash > /etc/bash_completion.d/poetry.bash-completion
+poetry completions bash > /etc/bash_completion.d/poetry
 
 # Fish
 poetry completions fish > ~/.config/fish/completions/poetry.fish