Refactor: change "folder" to "directory" where needed.

This commit fixes every instance in which the word "folder" is
incorrectly used instead of "directory".

pages/common/tokei.md

@@ -2,18 +2,18 @@
 
 > A program that prints out statistics about code.
 
-- Get a report on the code in a folder and all subfolders:
+- Get a report on the code in a directory and all subdirectories:
 
-`tokei {{path/to/folder}}`
+`tokei {{path/to/directory}}`
 
-- Get a report for a folder excluding `.min.js` files:
+- Get a report for a directory excluding `.min.js` files:
 
-`tokei {{path/to/folder}} -e {{*.min.js}}`
+`tokei {{path/to/directory}} -e {{*.min.js}}`
 
-- Print out statistics for individual files in a folder:
+- Print out statistics for individual files in a directory:
 
-`tokei {{path/to/folder}} --files`
+`tokei {{path/to/directory}} --files`
 
 - Get a report for all files of type Rust and Markdown:
 
-`tokei {{path/to/folder}} -t={{Rust}},{{Markdown}}`
+`tokei {{path/to/directory}} -t={{Rust}},{{Markdown}}`