Fix: deprecated filter warning message

[granddaifuku]

Overview

Currently, a warning message about the deprecated filter get is displayed as follows:

warning: use of deprecated filter `get` in [templates], please use the `?.` operator instead.
For example: `{{ hooks | get: "pre" | nl }}` can be written `{{ hook?.pre | nl }}`

However, I believe {{ hooks | get: "pre" | nl }} can be converted to {{ hooks?.pre | nl }} (not hook but hooks), and I've made this adjustment.

By the way, thank you for the fantastic shell plugin manager!

[rossmacarthur]

Thanks! My bad