Improve pagination

[pauljickling]

Currently only have previous page, and next page. This is fine as a start, but we should provide numbered links as well.

[evertonfraga]

Those would be especially useful on mobile:

• Add an # anchor on the next page link, so the user lands on the video section after clicking in the pagination links.
• Add page number indicator before videos

[pauljickling]

@evertonfraga can you elaborate on why you think the first suggestion would be helpful for mobile?

[evertonfraga]

It saves some user effort to scroll past the header and event details text. Some might even think the pagination didn't work.