edited landingsUS vignette

vignettes/landingsUs.Rmd

@@ -1,5 +1,5 @@
 ---
-title: "landingsUs"
+title: "Pull US landings data from STOCKEFF"
 output: rmarkdown::html_vignette
 vignette: >
   %\VignetteIndexEntry{landingsUs}
@@ -17,3 +17,13 @@ knitr::opts_chunk$set(
 ```{r setup}
 library(comlandr)
 ```
+
+US landings by trip are pulled from STOCKEFF via `get_comland_raw_data()` and grouped by year, month, negear, toncl2, nespp3, nespp4, area, utilcd, mesh, market_code from which spplivlb, sppvalue, and spplndlb are summed.
+
+* Mesh category (`MESHCAT`) is then defined as either `SM` (<= 3 inches) or `LG` (> 3 inches) depending on whether a trip reported a mesh size
+
+* Depending on `useLanded` argument meat weight or live weight is used for shellfish species (NESPP3 codes for shellfish are 743:800). Use `get_species()` or `get_species_itis()` to associate common or scientific names to these shellfish codes
+
+* Fish parts are removed. For a list of removed fish part codes, see vignette("fishPartsRemoved")
+
+* All weight is converted from lbs to metric tons