Update rules/Proj0503.md

Co-authored-by: Laura Kramer <[email protected]>

Author: Corniel

rules/Proj0503.md

@@ -8,9 +8,9 @@ Using a [NuGet](https://www.nuget.org) package implies that you
 and/or your company explicitly agree with the legally binding conditions of the
 license and the copyright of the owner of the package.
 
-If a third-party package license comes with a custom license (other then one
+If a third-party package license comes with a custom license (other than one
 specified by the [SPDX](https://spdx.dev)), this rule ensures that the license
-must have been aproved.
+must have been approved.
 
 To aprove a license, a `<<ThirdPartyLicense>` node has to be added with a
 matching include and a hash of the license file. That hash is communicated for