Problem: Static page alert HTML styling element documentation is out of date (using BS5 alert classes)

### Related docs

* https://www.accesstomemory.org/docs/2.10/user-manual/administer/static-pages/#boxes-and-dividers

Affects any post-BS5 upgrade version, but most importantly, the current v2.10 documentation.

### Issue noted

Specifically, the section that mentions how the BS5 alerts can be used.

Currently it says that using the inline element of `style="alert"` will work. In fact, all of these examples should use `class` instead, i.e.

### Recommended fix

The examples should be as follows:

```

```

I wanted to include an updated screenshot of the results for you on this issue as well, but have since discovered that attempting to update a static page with any HTML content results in a 403 Forbidden error. I have confirmed that the above works on a client test site, but because they havea custom theme, the display of the `alert-primary` and `alert-secondary` colors are different than what would display in a default installation, and should therefore not be used for the public docs.

Open the related static-pages documentation page and find the “boxes and dividers” section describing Bootstrap 5 alerts. Replace the examples’ style attributes with the class-based alert markup shown in the issue, then review the rendered documentation to confirm each example displays with the intended alert styling.

Written by the indexing model from the issue text.