Updated wording on download page
Updated wording on download page

Trying to make it more clear that OSS support is found on the mailing
lists and TW is available for commercial support.

ashwanthkumar/gocd.github.io,jmnarloch/gocd.github.io,markandan/www.go.cd,jyotisingh/www.go.cd,grahamc/gocd.github.io,jmnarloch/gocd.github.io,arvindsv/gocd.github.io,markandan/www.go.cd,gocd/gocd.github.io,ketan/www.go.cd,nyuday/www.go.cd,ashwanthkumar/gocd.github.io,jyotisingh/www.go.cd,ketan/www.go.cd,gocd/gocd.github.io,arvindsv/gocd.github.io,ketan/www.go.cd,arvindsv/www.go.cd,jmnarloch/gocd.github.io,arvindsv/www.go.cd,gocd/www.go.cd,kmugrage/gocd.github.io,arvindsv/gocd.github.io,kmugrage/gocd.github.io,nyuday/www.go.cd,grahamc/gocd.github.io,nyuday/www.go.cd,ashwanthkumar/gocd.github.io,gocd/www.go.cd,ketan/gocd.github.io,GaneshSPatil/www.go.cd,GaneshSPatil/www.go.cd,arvindsv/www.go.cd,gocd/gocd.github.io,kmugrage/gocd.github.io,ketan/gocd.github.io,GaneshSPatil/www.go.cd,ketan/gocd.github.io,gocd/gocd.github.io,gocd/www.go.cd,grahamc/gocd.github.io,gocd/www.go.cd,GaneshSPatil/www.go.cd,markandan/www.go.cd,jyotisingh/www.go.cd