Update user-manual.md

[Bear2let]

Switch in parts name between ToF and IMU sensors.

What This PR Changes

• There is an swap between parts name concerning the ToF and IMU sensors.

Contribution Guidelines

• I confirm that I have read the contribution guidelines and comply with them.

[jcarolinares]

@jhansson-ard I confirm user is right in case it helps, double checked

[jhansson-ard]

@Bear2let thank you for you contribution!

@jcarolinares thank you for double checking 🙏🏼

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
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