Update Files.ino to with with Nano ESP32

[VeloSteve]

On modern Arduinos such as the Nano ESP32 file names require a leading "/" to be recognized. This simply replaces "example.txt" with "/example.txt" in five places.

[CLAassistant]

All committers have signed the CLA.

[github-actions[bot]]

Memory usage change @ 9fc018fd5531f0b2ae11076d495dc7b63aeb0ac3

Board	flash	%	RAM for global variables	%
arduino:avr:leonardo	:small_red_triangle: 0 - +220	0.0 - +0.77	:small_red_triangle: 0 - +2	0.0 - +0.08
arduino:avr:mega	:small_red_triangle: 0 - +222	0.0 - +0.09	:small_red_triangle: 0 - +4	0.0 - +0.05
arduino:avr:nano	:small_red_triangle: 0 - +222	0.0 - +0.72	:small_red_triangle: 0 - +4	0.0 - +0.2
arduino:mbed_nano:nano33ble	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_nano:nanorp2040connect	:small_red_triangle: 0 - +1	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed_portenta:envie_m7:target_core=cm4	N/A	N/A	N/A	N/A
arduino:mbed_portenta:envie_m7	N/A	N/A	N/A	N/A
arduino:megaavr:nona4809	:small_red_triangle: 0 - +221	0.0 - +0.45	0 - 0	0.0 - 0.0
arduino:sam:arduino_due_x_dbg	0 - 0	0.0 - 0.0	N/A	N/A
arduino:samd:mkrzero	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board|`examples/CardInfo`
flash|%|`examples/CardInfo`
RAM for global variables|%|`examples/Datalogger`
flash|%|`examples/Datalogger`
RAM for global variables|%|`examples/DumpFile`
flash|%|`examples/DumpFile`
RAM for global variables|%|`examples/Files`
flash|%|`examples/Files`
RAM for global variables|%|`examples/NonBlockingWrite`
flash|%|`examples/NonBlockingWrite`
RAM for global variables|%|`examples/ReadWrite`
flash|%|`examples/ReadWrite`
RAM for global variables|%|`examples/listfiles`
flash|%|`examples/listfiles`
RAM for global variables|% -|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|-|- `arduino:avr:leonardo`|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|220|0.77|2|0.08|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 `arduino:avr:mega`|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|222|0.09|4|0.05|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 `arduino:avr:nano`|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|222|0.72|4|0.2|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 `arduino:mbed_nano:nano33ble`|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 `arduino:mbed_nano:nanorp2040connect`|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|1|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 `arduino:mbed_portenta:envie_m7:target_core=cm4`|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A `arduino:mbed_portenta:envie_m7`|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A|N/A `arduino:megaavr:nona4809`|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|221|0.45|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0 `arduino:sam:arduino_due_x_dbg`|0|0.0|N/A|N/A|0|0.0|N/A|N/A|0|0.0|N/A|N/A|0|0.0|N/A|N/A|0|0.0|N/A|N/A|0|0.0|N/A|N/A|0|0.0|N/A|N/A `arduino:samd:mkrzero`|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0|0|0.0

Click for full report CSV

``` Board,examples/CardInfo
flash,%,examples/CardInfo
RAM for global variables,%,examples/Datalogger
flash,%,examples/Datalogger
RAM for global variables,%,examples/DumpFile
flash,%,examples/DumpFile
RAM for global variables,%,examples/Files
flash,%,examples/Files
RAM for global variables,%,examples/NonBlockingWrite
flash,%,examples/NonBlockingWrite
RAM for global variables,%,examples/ReadWrite
flash,%,examples/ReadWrite
RAM for global variables,%,examples/listfiles
flash,%,examples/listfiles
RAM for global variables,% arduino:avr:leonardo,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,220,0.77,2,0.08,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:avr:mega,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,222,0.09,4,0.05,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:avr:nano,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,222,0.72,4,0.2,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_nano:nano33ble,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_nano:nanorp2040connect,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,1,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:mbed_portenta:envie_m7:target_core=cm4,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A arduino:mbed_portenta:envie_m7,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A arduino:megaavr:nona4809,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,221,0.45,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 arduino:sam:arduino_due_x_dbg,0,0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A,0,0.0,N/A,N/A arduino:samd:mkrzero,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0 ```