Updated _sidebar (markdown)

_sidebar.md

@@ -1,8 +1,10 @@
 ## ERPNext 
-####Community Wiki
+#### Community Wiki
+
 ![](https://erpnext.com/assets/frappe_theme/img/erp-icon.svg)
 
 #### External Links
+
 * [ERPNext Homepage](https://erpnext.com/)
 * [Frappe Wiki](https://github.com/frappe/frappe/wiki)
 * [Bench Wiki](https://github.com/frappe/bench/wiki)
@@ -19,6 +21,10 @@
 - [Install ERPNext on Debian based systems](Install ERPNext on Debian based systems)
 - [Install ERPNext on RedHat based systems](Install ERPNext on RedHat based systems)
 
+#### Pull Request Guides
+
+- [Pull Request Guidelines](https://github.com/frappe/erpnext/wiki/Pull-Request-Guidelines)
+
 #### Release Notes
 
 * [V8 Release Notes](https://github.com/frappe/erpnext/wiki/ERPNext-Version-8)
@@ -27,6 +33,7 @@
 
 
 #### Information Pages
+
 * [Community Developed Custom Scripts](Community Developed Custom Scripts)
 * [Country wise Chart of Accounts](Country wise Chart of Accounts)
 * [Developer Docs](Developer Docs)
@@ -69,4 +76,3 @@
 
 
 
-