Standardize syntax for parameter values in the docstrings

[joelostblom]

This is a low priority observation. Currently we use a mix of double (formatted as code) and single (formatted as italics) backticks in doc strings. E.g. the Chart page formats methods as code and parameter values in italics:

whereas the doc on Projection formats everything as code:

In JupyterLab, the docstrings are not formatted; in VS Code, both single and double backticks are formatted as code (but the type hints are not formatted):

We currently mostly use single backticks, which is also more consistent with how the parameter values from the the automatic type hints are formatted as italics in the docs.

Personally I probably find it a bit easier to read when using double backticks, but I don't have a strong preference and not sure it's worth the effort to standardize, but wanted to note it down.