Add sudoers tip from @yannickoo.

tips.md

@@ -1,4 +1,16 @@
-Useful things
+### Useful things
+
+Add this to your /etc/sudoers (it is recommended to use `visudo` command to edit that file!) to skip sudo password prompts during vagrant operations:
+```
+# Vagrant sudoers config
+Cmnd_Alias VAGRANT_EXPORTS_ADD = /usr/bin/tee -a /etc/exports
+Cmnd_Alias VAGRANT_NFSD = /sbin/nfsd restart
+Cmnd_Alias VAGRANT_EXPORTS_REMOVE = /usr/bin/sed -E -e /*/ d -ibak /etc/exports
+Cmnd_Alias VAGRANT_HOSTS_ADD = /bin/sh -c echo "*" >> /etc/hosts
+Cmnd_Alias VAGRANT_HOSTS_REMOVE = /bin/sed -i -e /*/ d /etc/hosts
+%admin ALL=(root) NOPASSWD: VAGRANT_EXPORTS_ADD, VAGRANT_NFSD, VAGRANT_EXPORTS_REMOVE, VAGRANT_HOSTS_ADD, VAGRANT_HOSTS_REMOVE
+```
+
 
 Attention: This might be out of date. Updated version coming soon!