Stop using Async eliding in TeamsHookClient.PostAsync

[ArminShoeibi]

Hello there, I am using your library and I Call PostAsync inside of try-catch blocks.
According to this demonstration, it's better to use async-await.

Source: https://www.linkedin.com/posts/moientajik_dotnet-csharp-infographic-activity-6917950412465561600-0F1U?utm_source=share&utm_medium=member_desktop