ratios_and_interpolations: updated 'gitignore for documentation
ratios_and_interpolations: added some more detail to documentation such as prerequisites as well as changed the sectioning to be more consistent with the underlying program structure
analysis_etass_Ds: moved from value,error syntax to val,dval syntax throughout to be consistent with updated ratio computation functions
hadron_obs: changed object counting to be independent of legend
ratios_and_interpolations: began extracting the various sub-steps of the driver function into subroutines so that the driver function here can act as a simple template for user driver functions