Add Devcontainer for Jekyll build

[wsciaroni]

This is an enhancement or feature.

Summary

As a developer, I want to keep my projects' dependencies isolated during development.

Context

This is a quality of life improvement for developers consuming this project.

The What

Visual Studio Code is my IDE of choice when working FOSS projects. It has support for containerized development with very little configuration on the developer's side.

How

To use this, simply install the following:

• VS Code
• Containerized Development Extension
• Docker

Then, open the container with VSCode. You should be prompted to "Reopen in a container".

This config automatically takes care of port forwarding for you.