Improve layout structure so users don't have to name posts "post"
By moving default to a page layout and posts to default, any section can
be a post. Some users were confused when they had posts that were not
named as such. No need to impose naming conventions on people.
Don't duplicate site title in home page TITLE tag (#78)
Let's say your `.Site.Title` is "My Website". The code grabs `.Site.Title`, and then then checks to see if there's a `.Title`. When you're on the homepage, `.Title` is equivalent to `.Site.Title`, so that the browser bar will read:
> My Website | My Website
If we qualify `.Title` by confining to the `.Params` namespace, then the site title isn't duplicated:
```<title>{{ block "title" . }}{{ .Site.Title }} {{ with .Params.Title }} | {{ . }}{{ end }}{{ end }}</title>```
> My Website
But it still picks up `.Title` from posts and pages, where a content title exists in front matter:
> My Website | About Me