specification / proportions image

Nitpick

https://github.com/badges/shields/blob/master/spec/SPECIFICATION.md

the image showing the padding takes far more cognitive effort than it should

There are labels on all four sides of the image with no consistency and - in general - goes against drafting best-practices

**Current Bad**: *Brain hurts looking at it*
```text
4px 4px (horizontal followed by vertical)
↔ ↕
6px ↔ Label Status ↔ 6px (horizontal dimensions on the "y" axis)
↕ ↔
4px 4px (vertical followed by horizontal)
```

re horizontal dimensions on the "y" axis:
[here's an analogy](https://avasqu20.files.wordpress.com/2014/05/pushpulldoors.jpg)

the two vertical labels should both be on the same **side** (which side, doesn't matter)
there is room to place all 4 horizontal labels along the top or bottom

**Proposed Good:** *I can tell what's going on here even as text!*
```text
4px ↕
Label Status
4px ↕
↔ ↔ ↔ ↔
6px 4px 4px 6px
```

[(also the depicted values may be wrong?)](https://github.com/badges/shields/issues/1071)

I can track down photoshop if need be (can't stand gimp)

Start with SPECIFICATION.md and inspect the padding image described in the issue; also review issue #1071 for the possibly incorrect depicted values. Replace the image with a clearer, consistently labeled proportion diagram, then verify that the documentation renders it correctly.

Written by the indexing model from the issue text.