Make compatibility table dynamic

**Problem**

The compatibility table in the [Prerequisites] page maps the STK versions supported by a PySTK release. This page gets updated every release. However, if a user reads and old version, this person may not be aware about new supported versions.

**Solution**

We could have a `compatibility.json` file placed next to our `versions.json`. Its format would be:

```json
{
"2025R2": ["13.0", "0.2.0"],
"2025R1": ["12.10", "0.1.1"],
...
}
```

Then, we can build the compatibility table by using a JS script that fetches it, reads its content, and populates the table.

Start by locating the Prerequisites page and the existing versions.json file. Review how the compatibility table is currently built, then add compatibility.json beside versions.json and connect the page's JavaScript to fetch it and populate the table. Done means supported STK and PySTK versions appear dynamically for readers of any release.

Written by the indexing model from the issue text.