Don't consider a "maximum tag depth" of 1 to be concerning

Every tag has at least a tag depth of 1, so there's no need to flag it
as a reason for concern. This change is done a bit kludgily, by
changing the scale factor for this statistic from 1 to 1.001, but it
has the desired effect of subtracting one from the number of stars
computed for any reasonable tag depth.

Author: mhagger

sizes/output.go

@@ -379,7 +379,7 @@ func (s HistorySize) TableString(threshold Threshold, nameStyle NameStyle) strin
 
 			S("History structure",
 				I("Maximum history depth", nil, s.MaxHistoryDepth, counts.MetricPrefixes, " ", 500e3),
-				I("Maximum tag depth", s.MaxTagDepthTag, s.MaxTagDepth, counts.MetricPrefixes, " ", 1),
+				I("Maximum tag depth", s.MaxTagDepthTag, s.MaxTagDepth, counts.MetricPrefixes, " ", 1.001),
 			),
 
 			S("Biggest checkouts",