Fix code tags alignment on browsers that use different default baseline

[vlakoff]

Follow-up to #153 (and the subsequent #154).

On browser Pale Moon, the code tags are shifted up, which makes reading the documentation quite tedious. That seems to be because Pale Moon applies a different default baseline, closer to the specifications, than Firefox and Chrome.

For more details you may read this topic on Pale Moon forum.

[driesvints]

Please post a screenshot of how this fixes something, thanks

[wolfbeast]

Regression from #153 and #154

This PR fixes the following current behavior:

After patch:

[driesvints]

And the behavior in Chrome, Safari, Firefox, Edge stays the same?

[wolfbeast]

It should, considering they apparently already use middle as the default behaviour if not specified. Made a quick test in Firefox since I have that readily available and it's fine.