adds Gauss as unit for magnetic flux densities

[bodokaiser]

Related #151

[github-actions]

Benchmark Results

	main	b56194e...	main/b56194e251157a...
Quantity/creation/Quantity(x)	3.41 ± 0.01 ns	3.41 ± 0.01 ns	1
Quantity/creation/Quantity(x, length=y)	3.11 ± 0.001 ns	3.11 ± 0.01 ns	1
Quantity/with_numbers/*real	4.02 ± 0.01 ns	3.1 ± 0.01 ns	1.29
Quantity/with_numbers/^int	8.05 ± 2.2 ns	8.05 ± 2.2 ns	1
Quantity/with_numbers/^int * real	8.67 ± 2.2 ns	8.67 ± 2.2 ns	1
Quantity/with_quantity/+y	4.04 ± 0.001 ns	4.04 ± 0.001 ns	1
Quantity/with_quantity//y	3.41 ± 0.01 ns	3.42 ± 0.011 ns	0.997
Quantity/with_self/dimension	3.1 ± 0.01 ns	3.1 ± 0.01 ns	1
Quantity/with_self/inv	3.11 ± 0.01 ns	3.11 ± 0.01 ns	1
Quantity/with_self/ustrip	2.79 ± 0.01 ns	2.79 ± 0.01 ns	1
QuantityArray/broadcasting/multi_array_of_quantities	0.145 ± 0.0019 ms	0.148 ± 0.0028 ms	0.979
QuantityArray/broadcasting/multi_normal_array	0.0529 ± 0.00023 ms	0.0528 ± 0.00017 ms	1
QuantityArray/broadcasting/multi_quantity_array	0.155 ± 0.0016 ms	0.155 ± 0.0012 ms	1
QuantityArray/broadcasting/x^2_array_of_quantities	23 ± 1.5 μs	22.9 ± 1.4 μs	1.01
QuantityArray/broadcasting/x^2_normal_array	4.22 ± 0.95 μs	4.18 ± 1.1 μs	1.01
QuantityArray/broadcasting/x^2_quantity_array	7.04 ± 28 μs	7.03 ± 28 μs	1
QuantityArray/broadcasting/x^4_array_of_quantities	0.0787 ± 0.0005 ms	0.0787 ± 0.00046 ms	1
QuantityArray/broadcasting/x^4_normal_array	0.0467 ± 0.0002 ms	0.0467 ± 0.00018 ms	1
QuantityArray/broadcasting/x^4_quantity_array	0.053 ± 0.00018 ms	0.053 ± 0.00016 ms	1
time_to_load	0.166 ± 0.0017 s	0.164 ± 0.00066 s	1.01

Benchmark Plots

A plot of the benchmark results have been uploaded as an artifact to the workflow run for this PR.
Go to "Actions"->"Benchmark a pull request"->[the most recent run]->"Artifacts" (at the bottom).

[bodokaiser]

@MilesCranmer Hi Miles, can you check the PR?

[MilesCranmer]

Hey, sorry for completely missing this.

Can you document it within the docs for Tesla? See the other doc strings for examples of the format used. e.g., hours is documented within the docstring for seconds.

[bodokaiser]

@MilesCranmer I updated the PR accordingly