Comment custom files on minimal configuration documentation (#767)

### Prerequisites

Put an `x` into the box(es) that apply:

- [X] This pull request fixes a bug.
- [ ] This pull request adds a feature.
- [ ] This pull request introduces breaking change.

### Description

This pull request allows a user to follow the Getting started
documentation and successfully build a hugo site using the hugo-coder
theme.

Currently, if you just follow the quick-start documentation using the
[minimal
config.toml](https://github.com/luizdepra/hugo-coder/blob/main/docs/configurations.md#complete-example)https://github.com/luizdepra/hugo-coder/blob/main/docs/configurations.md#complete-example
you won't be able to start the server, due the following errors

The issue is being solved by simply commenting the custom files on the
documentation, so anyone that follows the documentation will be able to
run the hugo site.

### Issues Resolved

- #766 

### Checklist

Put an `x` into the box(es) that apply:

#### General

- [X] Describe what changes are being made
- [X] Explain why and how the changes were necessary and implemented
respectively
- [X] Reference issue with `#<ISSUE_NO>` if applicable

#### Resources

- [ ] If you have changed any SCSS code, run `make release` to
regenerate all CSS files

#### Contributors

- [X] Add yourself to `CONTRIBUTORS.md` if you aren't on it already

Signed-off-by: Lucas de Oliveira <lucasvitalate@gmail.com>
Co-authored-by: Luiz F. A. de Prá <luizdepra@users.noreply.github.com>