Update typo in README.md (#96)

Fixed a spelling error.

README.md

@@ -30,7 +30,7 @@ Active development is happening today to build Android and iOS SDKs against the
 * .NET MAUI previews Q4 2020 through Q3 2021
   * [Renderer architecture revisions](https://github.com/dotnet/maui/issues/28)
   * Source solution and project simplification
-  * Completete approved proposals
+  * Complete approved proposals
   * Implement MVU
 * .NET MAUI release candidate September 2021
 * .NET MAUI general availability November 2021