docs boards native_sim: Improve FUSE FS access description

The FUSE driver allows accessing a possible filesystem, independently
of the underlaying device, so let's correct the description so we do
not mix "flash" with "filesystem".

Also, one does not need to create the 'flash' folder these days. The
FUSE library will if needed.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>

Author: aescolar

boards/native/native_sim/doc/index.rst

@@ -469,7 +469,7 @@ The following peripherals are currently provided with this board:
   Some more information can be found in :ref:`the emulators page <emul_flash_simu_brief>`.
 
   The flash content can be accessed from the host system, as explained in the
-  `Host based flash access`_ section.
+  `Host (FUSE) filesystem access`_ section.
 
 **Input events**
   Two optional native input drivers are available:
@@ -646,21 +646,18 @@ All :ref:`available HW emulators <emulators>` can be used with native_sim.
 
 .. _native_fuse_flash:
 
-Host based flash access
-***********************
+Host (FUSE) filesystem access
+*****************************
 
-If a flash device is present, the file system partitions on the flash
-device can be exposed through the host file system by enabling
-:kconfig:option:`CONFIG_FUSE_FS_ACCESS`. This option enables a FUSE
-(File system in User space) layer that maps the Zephyr file system calls to
-the required UNIX file system calls, and provides access to the flash file
-system partitions with normal operating system commands such as ``cd``,
-``ls`` and ``mkdir``.
+When building Zephyr with a filesystem, the device partitions can be exposed through the host file
+system by enabling :kconfig:option:`CONFIG_FUSE_FS_ACCESS`. This option enables a FUSE
+(File system in User space) layer that mounts the simulated embedded filesystem in the host
+filesystem, maps the Zephyr file system calls to the required UNIX file system calls, and provides
+access to its partitions with normal operating system commands such as ``cd``, ``ls`` and ``mkdir``.
 
 By default the partitions are exposed through the directory :file:`flash/` in the
 current working directory. This directory can be changed via the command line
-option ``--flash-mount``. As this directory operates as a mount point for FUSE
-you have to ensure that it exists before starting the native_sim board.
+option ``--flash-mount``.
 
 On exit, the native_sim board application will take care of unmounting the
 directory. In the unfortunate case that the native_sim board application
@@ -707,7 +704,7 @@ host libC (:kconfig:option:`CONFIG_EXTERNAL_LIBC`):
      EEPROM, EEPROM emulator, :kconfig:option:`CONFIG_EEPROM_EMULATOR`, All
      Ethernet, :ref:`Eth native_tap <nsim_per_ethe>`, :kconfig:option:`CONFIG_ETH_NATIVE_TAP`, All
      Flash, :ref:`Flash simulator <nsim_per_flash_simu>`, :kconfig:option:`CONFIG_FLASH_SIMULATOR`, All
-     Flash, :ref:`Host based flash access <native_fuse_flash>`, :kconfig:option:`CONFIG_FUSE_FS_ACCESS`, All
+     FUSE, :ref:`Host based filesystem access <native_fuse_flash>`, :kconfig:option:`CONFIG_FUSE_FS_ACCESS`, All
      GPIO, GPIO emulator, :kconfig:option:`CONFIG_GPIO_EMUL`, All
      GPIO, SDL GPIO emulator, :kconfig:option:`CONFIG_GPIO_EMUL_SDL`, All
      I2C, I2C emulator, :kconfig:option:`CONFIG_I2C_EMUL`, All