Wrap filename with quotes (#762)

## Summary

Wrap filename with quotes

## How was it tested?

Signed-off-by: Zhizhen He <[email protected]>

Author: hezhizhen

docs/app/docs/index.md

@@ -21,7 +21,7 @@ In practice, Devbox works similar to a package manager like yarn – except the
 Devbox provides a lot of benefits over pure Docker containers, Nix Shells, or managing your own environment directly: 
 
 ### A consistent shell for everyone on the team
-Declare the list of tools needed by your project via a devbox.json file and run devbox shell. Everyone working on the project gets a shell environment with the exact same version of those tools.
+Declare the list of tools needed by your project via a `devbox.json` file and run devbox shell. Everyone working on the project gets a shell environment with the exact same version of those tools.
 
 ### Try new tools without polluting your laptop
 Development environments created by Devbox are isolated from everything else in your laptop. Is there a tool you want to try without making a mess? Add it to a Devbox shell, and remove it when you don't want it anymore – all while keeping your laptop pristine. Removing or changing a package in your dev environment is as easy as editing your `devbox.json`.