Rename and describe headers in output files

[Cecilia-Sensalari]

• Adjustment table files (both): headers are now clearer and are consistent between the two files.
• File listing the trios: one header was changed ("Focal_Species") to be consistent with the adjustment table headers.
• Ortholog peak database: "Mode" instead of "Ortholog_Mode" and removed the "Ortholog_Median" columns.
• Documentation (input_output.rst): added figures of adjustment tables with column description.