v1.2.0 to enable scan of WiFi networks

### Major Release v1.2.0

1. Enable scan of WiFi networks for selection in Configuration Portal. Check [PR for v1.3.0 - Enable scan of WiFi networks #10](khoih-prog/WiFiManager_NINA_Lite#10). Now you can select optional **SCAN_WIFI_NETWORKS**, **MANUAL_SSID_INPUT_ALLOWED** to be able to manually input SSID, not only from a scanned SSID lists and **MAX_SSID_IN_LIST** (from 2-6 for ESP8266-AT or 2-15 for other)
2. Minor enhancement to not display garbage when data is invalid
3. Tested with new [Arduino Core for STM32 v2.0.0](https://github.com/stm32duino/Arduino_Core_STM32) and add support to new STM32L5 boards.
4. Enhance MultiWiFi connection logic
5. Enhance debugging feature

Author: khoih-prog

README.md

@@ -52,7 +52,7 @@
   * [7. To use and input only one set of WiFi SSID and PWD](#7-to-use-and-input-only-one-set-of-wifi-ssid-and-pwd)
     * [7.1 If you need to use and input only one set of WiFi SSID/PWD](#71-if-you-need-to-use-and-input-only-one-set-of-wifi-ssidpwd)
     * [7.2 If you need to use both sets of WiFi SSID/PWD](#72-if-you-need-to-use-both-sets-of-wifi-ssidpwd)
-  * [8. To enable auto-scan of WiFi networks for selection in Configuration Portal](8-to-enable-auto-scan-of-wifi-networks-for-selection-in-configuration-portal)
+  * [8. To enable auto-scan of WiFi networks for selection in Configuration Portal](#8-to-enable-auto-scan-of-wifi-networks-for-selection-in-configuration-portal)
     * [8.1 Enable auto-scan of WiFi networks for selection in Configuration Portal](#81-enable-auto-scan-of-wifi-networks-for-selection-in-configuration-portal)
     * [8.2 Disable manually input SSIDs](#82-disable-manually-input-ssids)
     * [8.3 Select maximum number of SSIDs in the list](#83-select-maximum-number-of-ssids-in-the-list)