chore: Change grammar in high_availability.md (#5964)
chore: Change grammar in high_availability.md (#5964)

Update summary statement for high availability to use proper grammar.

Signed-off-by: mgmtadmin <812cbb7cdab9e92fca0aa23388f8979526cf19f3@gmail.com>
argoproj/argo-cd,argoproj/argo-cd,argoproj/argo-cd,argoproj/argo-cd,argoproj/argo-cd