HBASE-26099 Add 3.0.0-alpha-1 to download page (#3507)
HBASE-26099 Add 3.0.0-alpha-1 to download page (#3507)

Signed-off-by: Yulin Niu <13cbb72540c2e0f51eae32f4db63154be13b220d@apache.org>
apurtell/hbase,mahak/hbase,apurtell/hbase,ndimiduk/hbase,Apache9/hbase,ndimiduk/hbase,mahak/hbase,apurtell/hbase,mahak/hbase,Apache9/hbase,mahak/hbase,ndimiduk/hbase,ndimiduk/hbase,ndimiduk/hbase,Apache9/hbase,Apache9/hbase,mahak/hbase,apurtell/hbase,apurtell/hbase,Apache9/hbase,apurtell/hbase,mahak/hbase,ndimiduk/hbase,Apache9/hbase,apurtell/hbase,mahak/hbase,apurtell/hbase,Apache9/hbase,ndimiduk/hbase,Apache9/hbase,mahak/hbase,Apache9/hbase,ndimiduk/hbase,mahak/hbase,apurtell/hbase,mahak/hbase,ndimiduk/hbase,ndimiduk/hbase,Apache9/hbase,apurtell/hbase