docs: headers overflow into other elements

**What happened**:

When reviewing some documentation on the EKS-A site I noticed I couldn't use the horizontal scroll bar in the ["Clone Template to VM"](https://anywhere.eks.amazonaws.com/docs/reference/vsphere/customize-ovas/) section. Further inspection shows header tags overflow into elements preceding them and have a higher z-index value making it impossible to select the horizontal scroll bar.

**\ tag**

**\ tag**

**Anything else we need to know?**:

Firefox 102.5.0esr

Start by opening the linked “Clone Template to VM” documentation page in Firefox and inspect the h2 and h3 elements around the horizontal scrollbar. Reproduce the overlap and verify the fix by confirming the scrollbar is selectable and the headings no longer cover preceding elements.

Written by the indexing model from the issue text.