Guide on adding blog posts.

[argelius]

Write a comprehensive guide on how to add a blog post in README.md.

It should include all the steps necessary such as:

• Add a new author in both config.js and a {{NAME}}.markdown file
• Where to put blog post
• Blog header format
• Where to put images
• How to make a pull request.

When this is done we can refer to this guide when people want to write blog posts.