feat: refine portal flow and examples

examples/BasicPortal/platformio.ini

@@ -0,0 +1,26 @@
+[platformio]
+default_envs = esp8266
+src_dir = .
+
+[common]
+framework = arduino
+lib_ldf_mode = deep+
+lib_deps =
+    WiFiManager=symlink://../..
+
+[env:esp8266]
+extends = common
+platform = espressif8266
+board = d1_mini
+platform_packages =
+    platformio/framework-arduinoespressif8266 @ https://github.com/esp8266/Arduino.git#521ae60a89e64bb0d1eb7a0b7addf620ced5cad3
+
+[env:esp32]
+extends = common
+platform = https://github.com/pioarduino/platform-espressif32/releases/download/51.03.05/platform-espressif32.zip
+board = esp32dev
+build_unflags = -std=gnu++11
+build_flags =
+    -std=gnu++14
+    -DSOC_WIFI_SUPPORTED=1
+    -I${platformio.packages_dir}/framework-arduinoespressif32/libraries/Network/src