README.md in fillable-pdf-th-1.0.3 vs README.md in fillable-pdf-th-1.0.4

@@ -125,9 +125,22 @@
 # set font size in pdf form
 # default is 12.00
 pdf.set_size(15)
 ```
 
+```ruby
+# set checkbox mark style in pdf form
+# default is 'check' ✓
+# list style
+# - ✓ check
+# - ☓ cross
+# - ☐ square
+# - ◆ diamond
+# - ★ star
+# all checkbox type become same style
+pdf.set_checkbox_style('cross')
+```
+
 Once the PDF is filled out you can either overwrite it or save it as another file:
 
 ```ruby
 pdf.save
 pdf.save_as('output.pdf')