Add defaults to VendorPrefixes config options in Readme
Add defaults to VendorPrefixes config options in Readme

Change-Id: Ib182b9316987f448cc734b70fffcfed8e6e26258
Reviewed-on: http://gerrit.causes.com/44886
Tested-by: jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@brigade.com>
Reviewed-by: Joe Lencioni <1dd72cf724deaab5db236f616560fc7067b734e1@brigade.com>

philipgiuliani/scss-lint,gatero/scss-lint,leseulsteve/scss-lint,bkeepers/scss-lint,ingdir/scss-lint,ivantsepp/scss-lint,chatzipan/scss-lint,dwayhs/scss-lint,gajus/scss-lint,davecarter/scss-lint,cih/scss-lint,teoljungberg/scss-lint,baileyparker/scss-lint