Updates the post index template to use the correct style class.
Adds line breaks and a horizontal rule to the post index template so that there is more visual space between posts as well as a line separating each post entry.
Adds styling to the horizontal rule.
Note that the breaks and horizontal rule apply to the end of every blog post in the index, including the last one on the page for example:
Fixes #356
This PR:
Note that the breaks and horizontal rule apply to the end of every blog post in the index, including the last one on the page for example: