feat(docs): reorganize docs (#7136)

docs/details/libs/arduino_esp_littlefs.rst

@@ -0,0 +1,23 @@
+.. _arduino_esp_littlefs:
+
+====================
+Arduino ESP littlefs
+====================
+
+LittleFS is a little fail-safe filesystem designed for microcontrollers and integrated in the Arduino framework 
+when used with ESP32 and ESP8266.
+
+Detailed introduction:
+
+- https://github.com/esp8266/Arduino 
+- https://github.com/espressif/arduino-esp32
+
+
+Usage
+-----
+
+Enable :c:macro:`LV_USE_FS_ARDUINO_ESP_LITTLEFS` and define a :c:macro:`LV_FS_ARDUINO_ESP_LITTLEFS_LETTER` in ``lv_conf.h``.
+
+
+API
+---