docs: Added detailed description to `hasura deploy` command

### Is your proposal related to a problem?
When executing the `hasura deploy` , I was confused as to which was executed first, the metadata apply or the migrate apply.

It would be great if add the execution order of `migrate apply` and `metadata apply` to the description of the `hasura deploy` command.

### Describe the solution you'd like

Specifically, the following explanation in the documentation would be helpful.

```
The migrate and metadata are applied in the following order.
1. migrate apply
2. metadata apply

If the migration fails to apply, the metadata will not be applied.
```

### If the feature is approved, would you be willing to submit a PR?
Yes, I want to work for this :)