pandas: DOC: Generating docs doesn't work if path has whitespaces

Related to #20862

If there are spaces in the path where pandas is installed (e.g. /home/my user/my code/pandas), when building the documentation (i.e. ./doc/make.py html) seems to generate a long list of usage errors like those:

UsageError: %bookmark: too many arguments
UsageError: %bookmark -d: Can't delete bookmark 'ipy_savedir'