Use esp-flasher-stub stubs (#518)

* feat: Add a feature to use rust-stubs

* test: Fix tests

* feat: Replace C stubs with esp-flasher-stub stubs

* docs: Update source of the sutbs

Author: SergioGasquez

espflash/resources/README.md

@@ -1,7 +1,9 @@
 # Espflash Resources
 
-The bootloaders have been built by hand from ESP-IDF, using the `release/v5.1` branch:  
+The bootloaders have been built by hand from ESP-IDF, using the `release/v5.1` branch:
 https://github.com/espressif/esp-idf/tree/release/v5.1
 
-The flasher stubs are taken from the **espressif/esptool** repository:  
+The ESP32s flasher stubs are taken from the **esp-rs/esp-flasher-stub** repository:
+https://github.com/esp-rs/esp-flasher-stub/latests
+The ESP8266 flasher stub is taken from the **espressif/esptool** repository:
 https://github.com/espressif/esptool/tree/master/esptool/targets/stub_flasher