user-guide: Adding rest api guide

- Examples with cURL
- Examples with https://api.foundries.io/ota/

fixup! rm: factory-keys: Add version when factory-key dir were created

requirements.txt: bump toolbox to new version

Signed-off-by: Igor Opaniuk <[email protected]>

install-fioctl: Adding Token instruction and updated configurantion

In the configuration section, the --factory was coming out as one
long -.

boards: imx8mm: update flash instructions

Update flash instructions for i.MX 8M Mini EVK.

Signed-off-by: Igor Opaniuk <[email protected]>

Boards: add iMX8MM with SE050

Signed-off-by: Milosz Wasilewski <[email protected]>

README.md: add steps for building docs

Add steps needed for building documentation locally.

Signed-off-by: Igor Opaniuk <[email protected]>

reference-manual: linux-wic-installer: add n1sdp support

Signed-off-by: Ricardo Salveti <[email protected]>

linux: linux-layers: add instructions to customize the default BSP la…

…yers

Signed-off-by: Ricardo Salveti <[email protected]>

se050: importing secure objects (foundriesio#139)

succintly inform of the secure object import design

Signed-off-by: Jorge Ramirez-Ortiz <[email protected]>