docs: Document new config in doc/R.nvim.txt

doc/R.nvim.txt

@@ -644,8 +644,11 @@ command:
 |save_win_pos|        Save position of Rgui window (Windows only)
 |arrange_windows|     Restore position of R window (Windows only)
 |assign_map|          Choose what to convert into ' <- '
-|rnowebchunk|         Convert '<' into '<<>>=\n@' in Rnoweb files
+pipe_map            Choose what to convert into ' |> ' (or ' %>% ')
+use_native_pipe     Choose whether to use ' |> ' or ' %>% ' with pipe_map
+|rnowebchunk         Convert '<' into '<<>>=\n@' in Rnoweb files
 |rmdchunk|            Convert grave accent chunk into delimiters
+rproj_prioritise    Config to override with a .Rproj file, if one is present
 |objbr_place|         Placement of Object Browser
 |objbr_w|             Initial width of Object Browser window
 |objbr_h|             Initial height of Object Browser window