Homepage Largo Recent Posts: add support for n>3 posts

[benlk]

We didn't write the styles there to accommodate additional posts, but it should be a quick, 15-30m fix to add definitions for additional posts there, to stack them between the third post and the more button:

https://github.com/INN/umbrella-sfpublicpress/blob/22f1ada39ac1093e1912799b78d3bb3a551efc82/wp-content/themes/sfpublicpress/homepages/assets/less/homepage.less#L238-L242

• [ ] change this to have terms for d and e and so on, to the upper limit of the post's count

[benlk]

Row gap.