This reverts commit 39253d7bc9.

Add gitpod config

this commit adds support for Gitpod.io, a free automated
dev environment that makes contributing and generally working on GitHub
projects much easier. It allows anyone to start a ready-to-code dev
environment for any branch, issue and pull request with a single click.

update link for docs

Add id for cta section.

Add a / to href for HTML compliance

Correct a problem when using less than 3 blog article

In this case, the author is (badly) displayed. This patch hard limits blog posts to blog section.

create support for custom css

update video url