Move missing values later; update preface

_bookdown.yml

@@ -24,11 +24,11 @@ rmd_files: [
   "relational-data.Rmd",
   "numbers.Rmd",
   "logicals.Rmd",
-  "missing-values.Rmd",
   "strings.Rmd",
   "regexps.Rmd",
   "factors.Rmd",
   "datetimes.Rmd",
+  "missing-values.Rmd",
   "column-wise.Rmd",
 
   "import.Rmd",

preface-2e.Rmd

@@ -4,11 +4,16 @@ Welcome to the second edition of "R for Data Science".
 
 ## Major changes {.unnumbered}
 
--   The first part is renamed to "whole game" to reflect the entire data science cycle, including a chapter on data import.
--   In the wrangle part highlight improvements to dplyr that make data scientists' lives even easier, such as new functions for rectangling data, working with list columns, and column-wise and row-wise operations.
--   Data import also gains a whole part that goes beyond importing rectangular data to include chapters on working with spreadsheets, databases, and web scraping.
--   The iteration chapter gains a new case study on web scraping from multiple pages.
+-   The first part is renamed to "whole game" to reflect the entire data science cycle. It gains a new chapter that briefly introduces the basics of reading data from csv files.
+
+-   The wrangle part is now transform and gains new chapters on numbers, logical vectors, and missing values. These were previously parts of the data transformation chapter, but needed much more room.
+
+    We a new chapters on column-wise and row-wise operations.
+
+-   We've added a new set of chapters on import that goes beyond importing rectangular data to include chapters on working with spreadsheets, databases, and scraping data from the web.
+
 -   The modeling part has been removed. For modeling, we recommend using packages from [tidymodels](https://www.tidymodels.org/) and reading [Tidy Modeling with R](https://www.tmwr.org/) by Max Kuhn and Julia Silge to learn more about them.
+
 -   We've switched from the magrittr pipe to the base pipe.
 
 ## Acknowledgements {.unnumbered}