Remove font-size scaling

The purpose of this is unclear. It was added in "parse
/groups/:groupName markdown;" (347ee03) which is the commit that added
the markdown rendering of group descriptions, so maybe it was a
stylistic adjustment relative to whatever else was on the page at that
time.

A similar 94% font-size scaling is used in the custom Auspice splash
page (auspice-client/customisations/splash.js) as well as other parts of
the Auspice code base. The purposes of those are also unclear.

The main motivation for removing it here is that there was an internal
bug report¹ of a group's description rendering with what looks like
partially scaled fonts. The issue self-resolved without any code changes
and we were unable to understand what caused it. My suspicion is that
this font-size scaling is a contributing factor. It can't be the only
factor because it has been around for many years now and this is the
first report of such an issue. Maybe a recent browser update handles
scaled fonts poorly.

Another motivation is that, after seeing the unscaled version, the
scaled version has noticeably smaller text for what seems to be no
apparent reason. I think removing the scaling improves readability on
this page, but of course that is subjective.

¹ <https://bedfordlab.slack.com/archives/C0K3GS3J8/p1731343211138099>

static-site/src/components/sourceInfoHeading.jsx

@@ -24,9 +24,6 @@ const OverviewContainer = styled.div`
     width: 200px;
     padding: 0;
   }
-  a, p {
-    font-size: 94%;
-  }
 `;
 
 export const AvatarImg = styled.img`