Update usage doc for CLI "upgrades_analyzer"

[lixiliu]

Enhancement Request

Currently there's no documentation on the CLI command "upgrades_analyzers". The example_usage ipynb on the UpgradesAnalyzer is out of date, exploratory, and does not work with the installed environment.

[lixiliu]

Also the default location of the output files is relative to the user's local repo of buildstockbatch even if the working directory is not pointed there. This will fail if the user doesn't have buildstockbatch cloned. It also doesn't make sense since the installation of buildstock-query does not depend on buildstockbatch.

Suggest making the output file path relative to the current directory of the CLI instead.