Replace table with grid

[ChHecker]

In print-index, you used table. This is problematic for two reasons:

1. In the documentation, it says to use grid in your case. This also helps with accessibility.
2. When I restyle tables in my program using set rules, it also changes the acrostiche index.

grid is plug-and-play, so I just replaced it.

[Grisely]

Thank you for your PR.
I am perfectly open to changing that if it improves anything. I will give it a look soon.
For the first point I definitely agree that anything that improves accessibility should be prioritized.
Regarding your second point about the styles, would it not be the same problem with a grid? If you style grids with a set rule it will be applied to the acronyms index grid too. Let me know if I missed something there.

[ChHecker]

Usually, grids are used for stacking content horizontally and as such, you usually don't change their layout globally. tables, however, are frequently used in figures and therefore often need to have consistent formatting throughout a document, which can be easily enforced with set rules.

[Grisely]

I merge the changes in main after rebasing your branch on a newer version of main with a new version number to prepare the next version of the package. I will close the PR instead of merging. Thank you for your contribution. It will be included in the next version.