Update README.md with Rust crate and NuGet package stats

Signed-off-by: Tyler Cloutier <cloutiertyler@users.noreply.github.com>

Author: cloutiertyler

README.md

@@ -30,7 +30,11 @@
      
     <a href="https://github.com/clockworklabs/spacetimedb/blob/master/LICENSE.txt"><img src="https://img.shields.io/badge/license-BSL_1.1-00bfff.svg?style=flat-square"></a>
 </p>
-
+<p align="center">
+    <a href="https://crates.io/crates/spacetimedb"><img src="https://img.shields.io/crates/d/spacetimedb?color=e45928&label=Rust%20Crate&style=flat-square"></a>
+    &nbsp;
+    <a href="https://www.nuget.org/packages/SpacetimeDB.Runtime"><img src="https://img.shields.io/nuget/dt/spacetimedb.runtime?color=0b6cff&label=NuGet%20Package&style=flat-square"></a>
+</p>
 <p align="center">
     <a href="https://discord.gg/spacetimedb"><img src="https://img.shields.io/discord/1037340874172014652?label=discord&style=flat-square&color=5a66f6"></a>
     &nbsp;