Added Understand and implement your own Redux

[gregsnewby]

Added "Understand and implement your own Redux" under Redux > Getting Started

Formatting

Please follow the existing formatting for each entry. In order to get newlines without paragraph breaks, each entry should have two spaces at the end of the line after both the URL and the title. Also, two-space indents before the URL and the description. Example:

- **Link Title**<space><space>  
<space><space>http://example.com<space><space>  
<space><space>Link description here

Result:

• Link Title
  http://example.com
  Link description here

Please do not strip whitespace for existing entries!

[markerikson]

Appreciate the PR, but I don't feel that article is something that's worth adding to the list at this point.