docs/arduino-nano-33-ble: Add support for USB Flash

    Add support for USB flash
    Converted note content to a sub section on install bossac
    This closes: OSTC/planning/hw-enablement#30

Signed-off-by: Gururaj Shetty <gururaj.shetty@huawei.com>
2 jobs for !165 with bossac in 11 seconds (queued for 7 seconds)
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Status Job ID Name Coverage
  Compliance
passed #32060
dco

00:00:03

 
  Build
passed #32061
build-docs

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