Create placeholder files

In the Cookbook RFC, the author lists out some possible topics for the first articles. We should create placeholder files for those.

You can see an example of how to add new pages to this app here: https://github.com/ember-learn/cookbook/pull/1 You have to create the md file in the right place, and edit `pages.yml`.

Each placeholder should have a copy of the template in it, and a link to an inspirational resource:

```
For some writing inspiration, here's a blog post that covers some similar topics: [Title by Firstname Lastname](link)
```

We should not copy any blog posts we do not have permission to use.