Enlarge PR/Issue Icons

[bnb]

Enlarging the PR and Issue icons in feed for a bit of a better visual cue on what type of notification you're looking at in the feed would be awesome.

The icons that I'm specifically referring to:

[andrewhathaway]

Hi @bnb! Thanks for the issue. We can most certainly look in to this, see what fits and doesn't look to extreme.

[juliankay]

+1 I like the idea of increasing the size here