Use explicit key for Debian / Ubuntu repo (#2080)

Author: hongquan

book/installation.md

@@ -40,8 +40,8 @@ For Windows:
 For Debian & Ubuntu:
 
 ```sh
-curl -fsSL https://apt.fury.io/nushell/gpg.key | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/fury-nushell.gpg
-echo "deb https://apt.fury.io/nushell/ /" | sudo tee /etc/apt/sources.list.d/fury.list
+wget -qO- https://apt.fury.io/nushell/gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/fury-nushell.gpg
+echo "deb [signed-by=/etc/apt/keyrings/fury-nushell.gpg] https://apt.fury.io/nushell/ /" | sudo tee /etc/apt/sources.list.d/fury.list
 sudo apt update
 sudo apt install nushell
 ```