Added morris_sample and neighborhood_sample to sampling.py, Added some documentation for other functions.
Changed formatting of .readthedocs.yml to be compatible with [updated version of configuration file](https://docs.readthedocs.io/en/stable/config-file/v2.html).
EPlus output is now silent by default, with the option to make verbose with the `stdout_mode="Verbose"` keyword argument.
Fixed malformed `besos/data/example_xlsx.xlsx` file.