wifi_scan_example: Comments improved for readability
wifi_scan_example: Comments improved for readability

Rephrased the example's description to make it easier to understand
and made other grammatical fixes.

Signed-off-by: Piyush Shah <22b9c231e86e73b6822f10a284ad53e606c09e6d@espressif.com>

mashaoze/esp-idf,nineisk/esp-idf,www220/esp-idf,www220/esp-idf,Hermiedapwdrman/esp-idf,nineisk/esp-idf,nineisk/esp-idf,empoweredhomes/esp-idf,MIhanguangyi/esp-idf,armada-ai/esp-idf,armada-ai/esp-idf,MIhanguangyi/esp-idf,mashaoze/esp-idf,MIhanguangyi/esp-idf,espressif/esp-idf,Hermiedapwdrman/esp-idf,armada-ai/esp-idf,espressif/esp-idf,Hermiedapwdrman/esp-idf,www220/esp-idf,www220/esp-idf,MIhanguangyi/esp-idf,Hermiedapwdrman/esp-idf,www220/esp-idf,Hermiedapwdrman/esp-idf,armada-ai/esp-idf,mashaoze/esp-idf,nineisk/esp-idf,empoweredhomes/esp-idf,empoweredhomes/esp-idf,MIhanguangyi/esp-idf,empoweredhomes/esp-idf,mashaoze/esp-idf,mashaoze/esp-idf,empoweredhomes/esp-idf,espressif/esp-idf,espressif/esp-idf