Update cheatsheets

tldr/osx/afplay

@@ -20,6 +20,6 @@ source: https://github.com/tldr-pages/tldr.git
 
 `afplay --rate {{0.5}} {{path/to/file}}`
 
-- Play the first N seconds of a sound file:
+- Play the first `n` seconds of a sound file:
 
-`afplay --time {{seconds}} {{path/to/file}}`
+`afplay --time {{n}} {{path/to/file}}`

tldr/osx/du

@@ -24,10 +24,10 @@ source: https://github.com/tldr-pages/tldr.git
 
 `du -ah {{path/to/directory}}`
 
-- List the human-readable sizes of a directory and any subdirectories, up to N levels deep:
+- List the human-readable sizes of a directory and any subdirectories, up to `n` levels deep:
 
-`du -h -d {{2}} {{path/to/directory}}`
+`du -h -d {{n}} {{path/to/directory}}`
 
 - List the human-readable size of all `.jpg` files in subdirectories of the current directory, and show a cumulative total at the end:
 
-`du -ch {{*/*.jpg}}`
+`du -ch */*.jpg`

tldr/osx/tail

@@ -29,6 +29,6 @@ source: https://github.com/tldr-pages/tldr.git
 
 `tail -F {{path/to/file}}`
 
-- Show last 'count' lines in 'file' and refresh every 'seconds' seconds:
+- Show last `count` lines in a file and refresh every `seconds` seconds:
 
-`tail -n {{8}} -s {{10}} -f {{path/to/file}}`
+`tail -n {{count}} -s {{seconds}} -f {{path/to/file}}`