Add continue reading link

[amorphic]

This PR:

1. Adds a "Continue Reading" link at the bottom of each article's summary. This allows the reader to click directly through to the full article from the end of the summary rather than scroll back up to the Headline. The link is styled using the same "button" style as the article tags.

2. Updates the "Comments" link to the same style as the "Continue Reading" link and places them side-by-side to conserve vertical space:

[arulrajnet]

@amorphic Thanks for your PR. The buttons are not properly formatted when I tried with attila-demo source code

[amorphic]

Thanks for checking @arulrajnet. The buttons render correctly on my blog so I assumed they were good to go.

I'll looking into what's going wrong with the attila demo blog and update the PR accordingly.

[amorphic]

Thanks for checking @arulrajnet. The buttons render correctly on my blog so I assumed they were good to go.

I'll looking into what's going wrong with the attila demo blog and update the PR accordingly.

[amorphic]

@arulrajnet I've updated the PR and tested against my blog and the Attila demo site:

The change is actually much cleaner since the update too. Please let me know if you want any other changes.

[sio]

Are these links optional? I'd like to have the ability to opt out of rendering them.