legend cowplot tweaks

findex/src/plot_utils.R

src/assets/images/CW_Change_in_flooding_legend.png

src/assets/images/CW_Change_in_ice_cover_legend.png

src/assets/images/CW_Change_in_water_temperature_legend.png

src/assets/images/CW_Change_in_wind_patterns_legend.png

src/assets/images/CW_Drought_legend.png

src/assets/images/Climate_and_weather_legend.png

src/assets/images/FP_Overfishing_legend.png

src/assets/images/Fishing_pressure_legend.png

src/assets/images/H_Agricultural_extraction_legend.png

src/assets/images/H_Dams_legend.png

...s/images/H_Deforestation_and_associated_runoff_legend.png

src/assets/images/H_Industrial_extraction_legend.png

src/assets/images/H_Riparian_degradation_legend.png

src/assets/images/H_Urban_extraction_legend.png

src/assets/images/H_Wetland_drainage_legend.png

src/assets/images/Habitat_legend.png

src/assets/images/IS_Invasive_non-native_species_legend.png

src/assets/images/Invasive_species_legend.png

src/assets/images/P_Agricultural_effluents_legend.png