docs: add note about em unit in the column width jsdoc

[DiegoCardoso]

Description

Add a new paragraph to mention the issue of using em length unit in columns width.

Part of vaadin/flow-components#6260

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[vursen]

I've just noticed that the text on the docs website mentions an option of using the same font size for all the cells as an alternative to rem.

When length relative to the font size is needed, use instead the rem length unit -- or make sure that the font size is consistent across the cells.

I'm now thinking if it's important to mention this in the JSDoc too. What do you think?

[DiegoCardoso]

I've just noticed that the text on the docs website mentions an option of using the same font size for all the cells as an alternative to rem.

When length relative to the font size is needed, use instead the rem length unit -- or make sure that the font size is consistent across the cells.

I'm now thinking if it's important to mention this in the JSDoc too. What do you think?

I tried to be a bit more concise on the JSDoc, so that's why I didn't add it here.

[vaadin-bot]

This ticket/PR has been released with Vaadin 24.5.0.alpha1 and is also targeting the upcoming stable 24.5.0 version.