docs: update README with useful info

Signed-off-by: deadprogram <ron@hybridgroup.com>

Author: deadprogram

README.md

@@ -2,5 +2,105 @@
 
 [![Build](https://github.com/tinygo-org/tinyfs/actions/workflows/build.yml/badge.svg?branch=dev)](https://github.com/tinygo-org/tinyfs/actions/workflows/build.yml)
 
-TinyFS contains Go implementations of embedded filesystems.  The packages in
+TinyFS contains Go implementations of embedded filesystems. The packages in
 this module require CGo support and are [TinyGo](https://tinygo.org/) compatible.
+
+## Supported hardware
+
+You can use TinyFS with the following embedded hardware configurations:
+
+### Onboard Flash memory
+
+You can use TinyFS on processors that have onboard Flash memory in the area above where the compiled TinyGo program is running.
+
+### External Flash memory
+
+You can use TinyFS on an external Flash memory chip connected via SPI/QSPI hardware interface.
+
+See https://github.com/tinygo-org/drivers/tree/release/flash
+
+### SD card connected via SPI/QPI
+
+You can use TinyFS on an SD card connected via SPI/QSPI hardware interface.
+
+See https://github.com/tinygo-org/drivers/tree/release/sdcard
+
+## LittleFS
+
+The LittleFS file system is specifically designed for embedded applications.
+
+See https://github.com/littlefs-project/littlefs for more information.
+
+### Example
+
+This example runs on the RP2040 using the on-board flash in the available memory above where the program code itself is running:
+
+```
+$ tinygo flash -target pico -monitor ./examples/console/littlefs/machine/
+Connected to /dev/ttyACM0. Press Ctrl-C to exit.
+SPI Configured. Reading flash info
+==> lsblk
+
+-------------------------------------
+ Device Information:  
+-------------------------------------
+ flash data start: 10017000
+ flash data end:  10200000
+-------------------------------------
+
+==> format
+Successfully formatted LittleFS filesystem.
+
+==> mount
+Successfully mounted LittleFS filesystem.
+
+==> ls
+==> samples
+wrote 90 bytes to file0.txt
+wrote 90 bytes to file1.txt
+wrote 90 bytes to file2.txt
+wrote 90 bytes to file3.txt
+wrote 90 bytes to file4.txt
+==> ls
+-rwxrwxrwx    90 file0.txt
+-rwxrwxrwx    90 file1.txt
+-rwxrwxrwx    90 file2.txt
+-rwxrwxrwx    90 file3.txt
+-rwxrwxrwx    90 file4.txt
+==> cat file3.txt
+00000000: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f     !"#$%&'()*+,-./
+00000010: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f    0123456789:;<=>?
+00000020: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f    @ABCDEFGHIJKLMNO
+00000030: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f    PQRSTUVWXYZ[\]^_
+00000040: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f    `abcdefghijklmno
+00000050: 70 71 72 73 74 75 76 77 78 79                      pqrstuvwxy
+```
+
+After unplugging and reconnecting the RP2040 device (a hard restart):
+
+```
+$ tinygo monitor
+Connected to /dev/ttyACM0. Press Ctrl-C to exit.
+SPI Configured. Reading flash info
+==> mount
+Successfully mounted LittleFS filesystem.
+
+==> ls
+-rwxrwxrwx    90 file0.txt
+-rwxrwxrwx    90 file1.txt
+-rwxrwxrwx    90 file2.txt
+-rwxrwxrwx    90 file3.txt
+-rwxrwxrwx    90 file4.txt
+==> cat file3.txt
+00000000: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f     !"#$%&'()*+,-./
+00000010: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f    0123456789:;<=>?
+00000020: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f    @ABCDEFGHIJKLMNO
+00000030: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f    PQRSTUVWXYZ[\]^_
+00000040: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f    `abcdefghijklmno
+00000050: 70 71 72 73 74 75 76 77 78 79                      pqrstuvwxy
+```
+
+## FAT FS
+
+The FAT file system is not currently working, due to https://github.com/tinygo-org/tinygo/issues/3460.
+