Group element updates from same author

[Origin page](https://www.webcomponents.org/elements)

Its quite annoying to scroll though the whole list of elements that are updated when some author pushes an update to all of them

Start at the origin page, https://www.webcomponents.org/elements, and inspect how the list displays elements updated by the same author. The work is done when updates from one author are grouped so the page no longer shows a separate item for every element update.

Written by the indexing model from the issue text.