CODEOWNERS: Add code owner for everything in /Runtimes

Author: AnthonyLatsis

.github/CODEOWNERS

@@ -32,6 +32,7 @@
 # TODO: /README.md
 
 # Runtimes
+/Runtimes/                                 @etcwilde
 /Runtimes/**/*.cmake                       @etcwilde @compnerd @edymtt @justice-adams-apple
 /Runtimes/**/CMakeLists.txt                @etcwilde @compnerd @edymtt @justice-adams-apple
 /Runtimes/Core/cmake/caches/Vendors/Apple/ @etcwilde @shahmishal @edymtt @justice-adams-apple