Close #24 mv descriptive stats code into package

[egouldo]

• Convert descriptive summary table code to functions #24 create internal objectsfor prediction/effect id lists
• Convert descriptive summary table code to functions #24 add details for fn count_conclusions - and rebuild documentation
• Convert descriptive summary table code to functions #24 add fn to prepare sorensen summary data
• Convert descriptive summary table code to functions #24 switch to left_join to correctly filter data subsets
• Convert descriptive summary table code to functions #24 Add fun for summarising variables across data subsets
• Convert descriptive summary table code to functions #24 Add + update descriptive stat pipeline fns - add fns for preparing summary data for all, effects, and predictions subsets - add function arg check for prepare_diversity_summary_data - add targets wrapper fn for applying study summary stats functions
• Convert descriptive summary table code to functions #24 Add example code for summarise_study() and document fn
• Convert descriptive summary table code to functions #24 rebuild pkg and bump version
• - Convert descriptive summary table code to functions #24 add summary statistics to targets pipeline - Convert descriptive summary table code to functions #24 usethis::use_data on target output
• Convert descriptive summary table code to functions #24 rerun tar_make.R
• Increment version number to 2.0.0 - fix Convert descriptive summary table code to functions #24