FIX: App Installation Error Msg

[ilgooz]

When I try to install an app, say ignite app install -g github.com/ignite/apps it fails with the following error since there are no apps at the root of this repo.

✘ Error while loading app "github.com/ignite/apps": go mod tidy: error while running command go mod tidy: go: go.mod file not found in current directory or any parent directory; see 'go help modules': exit status 1

On such cases, we should display an error message that inform the user better about the situation. Something like: (@salmad3 to improve the text)

We can not find an app at the root of this repository, please make sure your repository url is correct. If you're trying to install an app under a sub folder don't forget to add the path at the end of your repository url. E.g. github.com/ignite/apps/appregistry.