[docs] for print style (#10452)

erpnext/docs/user/manual/en/setting-up/print/index.txt

@@ -1,5 +1,6 @@
 print-settings
 print-format-builder
+print-style
 print-headings
 letter-head
 address-template

erpnext/docs/user/manual/en/setting-up/print/print-style.md

@@ -0,0 +1,15 @@
+# Print Style
+
+Frappe/ERPNext comes with pre-set styles for your printed documents. You can also create new styles using CSS that can be applied to all your print formats.
+
+To create a new **Print Style** go to **Setup > Printing and Branding > Print Style**, or just type "print style" in the search bar.
+
+Here you can define the CSS rules for your print formats. These apply to both standard and custom print formats. To find out the various classes available, you can make a standard print format, open in a new page and see the source.
+
+To set a default style, you can go to [Print Settings](/docs/setup/print/print-settings)
+
+All Print Format styles are based on Bootstrap (Version 3) CSS Framework.
+
+<img class="screenshot" alt="Print Style" src="/docs/assets/img/setup/print/print-style.png">
+
+{next}