gitignore updates

Author: Susan Vanderplas

.gitignore

@@ -13,3 +13,4 @@ api_keys.R
 videos
 .Renviron
 _environment
+graveyard.html

_environment

@@ -1,13 +1,5 @@
-01-simulation_cache
-data
-01-simulation_files
-05-APIs_files
-06-pdf-tools_cache
-06-pdf-tools_files
-07-intro-interactive-graphics.html
-08-javascript-graphics.html
-08-javascript-graphics.rmarkdown
-09-big-data.html
-10-databases.html
-11-arrow-parquet.html
-12-memory-handling.html
+*_cache
+*_files
+*.html
+data/
+*.rmarkdown