codeowner: Add owners for examples in network category
New example folder `network` has been introduced in to
hold examples related to generic networking, not specifically to
ethernet nor wifi. This change however didn't assign code owners, so
only IDF maintainers could approve MRs.
Assigning code ownership to groups:
* network
* wifi
/examples/ethernet/ @esp-idf-codeowners/network
/examples/get-started/ @esp-idf-codeowners/system
/examples/mesh/ @esp-idf-codeowners/wifi
+/examples/network/ @esp-idf-codeowners/network @esp-idf-codeowners/wifi
/examples/openthread/ @esp-idf-codeowners/ieee802154
/examples/peripherals/ @esp-idf-codeowners/peripherals
/examples/protocols/ @esp-idf-codeowners/network @esp-idf-codeowners/app-utilities
