DOC: Backticks missing in pandas.DataFrame.query
#### Location of the documentation

https://pandas.pydata.org/docs/dev/reference/api/pandas.DataFrame.query.html

#### Documentation problem

![image](https://user-images.githubusercontent.com/12128514/110805248-31a1a000-8281-11eb-93bd-2281a2a43073.png)

#### Suggested fix for documentation

Backticks should be shown for the second `Area (cm^2)`.