fix typos in WiFiSTA.cpp (#4396)

* fix typos

* made return value description a bit more helpful

libraries/WiFi/src/WiFiSTA.cpp

@@ -224,8 +224,8 @@ wl_status_t WiFiSTAClass::begin()
 }
 
 /**
- * will force a disconnect an then start reconnecting to AP
- * @return ok
+ * will force a disconnect and then start reconnecting to AP
+ * @return true when successful
  */
 bool WiFiSTAClass::reconnect()
 {
@@ -337,7 +337,7 @@ bool WiFiSTAClass::config(IPAddress local_ip, IPAddress gateway, IPAddress subne
 
 /**
  * is STA interface connected?
- * @return true if STA is connected to an AD
+ * @return true if STA is connected to an AP
  */
 bool WiFiSTAClass::isConnected()
 {