Code review comment for ~athos-ribeiro/ubuntu-docker-images:update-templates-21.04-makefile

Oh, and what I've done for the README is that I removed the instructions related to "data" files and refactored the Installation section as following:
---
## Installing

### DevContainer

This repository contains a `.devcontainer` config folder to allow isolated-environment-controlled execution with [VScode](https://code.visualstudio.com/docs/remote/containers).

The DevContainer will provide you with a working environment out of the box. **You don't need any configuration.**

### Manually

```bash
git clone https://github.com/misterw97/RenderDown
sudo apt update -y && sudo apt install -y python3-mako python3-yaml
pip3 install -r RenderDown/requirements.txt
```