changed title.titleize to pretty_title

because we used title.titleize in a lot of places i made a method called
"pretty_title" and used it everywhere that it's needed
implemented description and keywords

updated the readme.md with instructions
added meta tags for  description and keywords on show page
added specs for testings the description is being used correctly
description, not body, should be displayed on list page
fixed typo and meta tags

fixed typo, it should be titleized not tileize
meta tags should close with "/>"
changed condition for yield

<% if content_for?(:seo_meta) %> is not required for yield(:seo_meta)
also updated the readme.md with the change
changed create_a_blog_post default options

changed create_a_blog_post default options so we don't need to call them
explicitly every time we want to create a blog
Merge pull request #6 from xskander/feature/default_schema_markup

default seo markup