Add LSv3 VM series to strategic service list

Author: johndowns

articles/reliability/availability-service-by-category.md

@@ -121,6 +121,7 @@ As mentioned previously, Azure classifies services into three categories: founda
 > | Virtual Machines: HBv3-series                        |
 > | Virtual Machines: HCv1-series                        |
 > | Virtual Machines: LSv2-series                        |
+> | Virtual Machines: LSv3-series                        |
 > | Virtual Machines: Mv2-series                         |
 > | Virtual Machines: NCv3-series                        |
 > | Virtual Machines: NCasT4 v3-series                   |