fix(apps.rs): fix formatting for description

[vdice]

Fixes formatting of description on apps info.

$ spin cloud apps info new-rust
Warning: You're using a pre-release version of Spin (2.4.0-pre0). This plugin might not be compatible (supported: >=1.3). Continuing anyway.
Name: new-rust
DescriptionMy new Spin app using the Rust SDK
URL: https://new-rust-oar3balb.fermyon.app

->

$ spin cloud apps info new-rust
Warning: You're using a pre-release version of Spin (2.4.0-pre0). This plugin might not be compatible (supported: >=1.3). Continuing anyway.
Name: new-rust
Description: My new Spin app using the Rust SDK
URL: https://new-rust-oar3balb.fermyon.app