Modified the reference to replacing the EIA Plant ID for units that have mismatched ORIS. Based on the output, it does not overwrite the EIA Plant ID.
Some minor editing/tweaks for clarity.
Clarified the data retrieval process for FACT API and added information about EIA ZIP and XLS.
Added reference to EIA boiler ID.
Added important note that crosswalk only includes units that were operational in 2018, excludes shutdowns and units commencing operation after 2018.
Elaborated on the important note that some units don't have generator IDs, noting that some gen IDs are populated by EPA staff based on research. Also noted that industrials don't report to EIA.