Update On-Site Emissions Table Reference

The table reference is out of date. This change updates the table reference and insert a simple display of the factors for easy reference by users.

Pull request overview

This pull request makes changes to (select all the apply):

[x] Documentation
[ ] Infrastructure (includes singularity image, buildstock batch, dependencies, continuous integration tests)
[ ] Sampling
[ ] Workflow Measures
[ ] Upgrade Measures
[ ] Reporting Measures
[ ] Postprocessing

Author pull request checklist:

[ ] Tagged the pull request with the appropriate label (documentation, infrastructure, sampling, workflow measure, upgrade measure, reporting measure, postprocessing) to help categorize changes in the release notes.
[ ] Added tests for new measures
[ ] Updated measure .xml(s)
[ ] Register values added to comstock_column_definitions.csv
[ ] Both options_lookup.tsv files updated
[ ] 10k+ test run
[ ] Change documentation written
[ ] Measure documentation written
[x] ComStock documentation updated
[ ] Changes reflected in example .yml files
[ ] Changes reflected in README.md files
[ ] Added 'See ComStock License' language to first two lines of each code file
[ ] Implements corresponding measure tests and indexing path in test/measure_tests.txt or/and test/resource_measure_tests.txt
[ ] All new and existing tests pass the CI

This will not be exhaustively relevant to every PR.

[ ] Perform a code review on GitHub
[ ] All related changes have been implemented: data and method additions, changes, tests
[ ] If fixing a defect, verify by running develop branch and reproducing defect, then running PR and reproducing fix
[ ] Reviewed change documentation
[ ] Ensured code files contain License reference
[ ] Results differences are reasonable
[ ] Make sure the newly added measures has been added with tests and indexed properly
[ ] CI status: all tests pass

# ComStock™, Copyright (c) 2023 Alliance for Sustainable Energy, LLC. All rights reserved.
# See top level LICENSE.txt file for license terms.