Rollup merge of #105666 - notriddle:notriddle/stab-baseline, r=GuillaumeGomez

rustdoc: align stability badge to baseline instead of bottom

| desc | img |
|------|-----|
| before | ![image](https://user-images.githubusercontent.com/1593513/207412598-3a6468ca-a169-4810-a689-4797688385df.png) |
| | |
| after | ![image](https://user-images.githubusercontent.com/1593513/207412720-b120269a-48a3-40e9-a9b0-6769bb05e104.png) |

Preview: http://notriddle.com/notriddle-rustdoc-demos/stab-baseline/test_dingus/index.html

Based on comment from rust-lang/rust#105509 (comment)

r? ``@joshtriplett``

Author: matthiaskrgr