Add post generation and publish tools

[ifosch]

One of the last steps we are missing to automate is the generation and publishing of the post for the episode being published.

One possible interesting approach could be to add a tool to generate the post, and another one to publish it. Add these steps to the README.md document.

[ifosch]

It's relevant to consider to use the image file from the script locally and push it to the blog, instead of linking against the Drive's URL directly. One detail for consideration is how to handle the possible clashes in image file names.