Add VectorNav VN-100 integration wiki page

[manankharwar]

What

Write a wiki page documenting FusionCore integration with the VectorNav VN-100 IMU.

Why

VectorNav is one of the most widely used IMU families in outdoor robotics (agriculture, construction, mining). The VN-100 specifically is the entry-level unit many teams use before upgrading to VN-200/300. A working integration guide makes FusionCore the default choice for VectorNav users on ROS 2.

Scope

• Which ROS 2 driver to use (`vectornav` package from TIER IV)
• Whether to use the driver's gravity subtraction or FusionCore's (`imu.remove_gravitational_acceleration` param)
• Topic remapping from VN-100 driver defaults to FusionCore's `imu.topic` param
• Noise values: VN-100 datasheet gyro noise density and what to put in FusionCore's `gyro_noise_*` params
• If the VN-100 is mounted at an angle, how to set the IMU frame in TF

Resources

• VN-100 datasheet: https://www.vectornav.com/products/detail/vn-100
• vectornav ROS 2 driver: https://github.com/dawonn/vectornav
• FusionCore IMU params: https://manankharwar.github.io/fusioncore/