Minor bug fixes and color enhancments

SWMPrExtension v1.1.1

• Updates to allow user to specify trend colors for create_sk_flextable_list function
• Additional updates to compensate for changes in Officer 0.3.3 flextable structure
• adding free_y argument to threshold_percentile_plot
• Minor fix to help files if searching by concept, e.g., `help.search('analyze', package = "SWMPrExtension")