Add Maria Shaldybin as Networking approver

Author: mariash

toc/working-groups/app-runtime-platform.md

@@ -274,6 +274,8 @@ areas:
     github: Gerg
   - name: Josh Russett
     github: jrussett
+  - name: Maria Shaldybin
+    github: mariash
   - name: Matthew Kocher
     github: mkocher
   - name: Patrick Lowin