Update docs and add doctests

[abhro]

Please see the commmit messages for relevant changes

[github-actions]

Benchmark Results

	main	87bd849...	main / 87bd849...
Quantity/creation/Quantity(x)	3.1 ± 0.01 ns	3.1 ± 0.01 ns	1
Quantity/creation/Quantity(x, length=y)	3.43 ± 1.6 ns	3.73 ± 0.01 ns	0.92
Quantity/with_numbers/*real	3.11 ± 0.01 ns	2.79 ± 0.01 ns	1.11
Quantity/with_numbers/^int	8.98 ± 1.5 ns	8.57 ± 1.5 ns	1.05
Quantity/with_numbers/^int * real	8.99 ± 1.6 ns	9.28 ± 1.7 ns	0.969
Quantity/with_quantity/+y	4.35 ± 0.001 ns	4.35 ± 0.001 ns	1
Quantity/with_quantity//y	3.11 ± 0 ns	3.42 ± 0.01 ns	0.909
Quantity/with_self/dimension	3.11 ± 0.01 ns	3.11 ± 0.001 ns	1
Quantity/with_self/inv	3.11 ± 0 ns	3.11 ± 0.01 ns	1
Quantity/with_self/ustrip	2.79 ± 0.01 ns	3.1 ± 0.01 ns	0.903
QuantityArray/broadcasting/multi_array_of_quantities	0.0874 ± 0.00081 ms	0.0875 ± 0.0067 ms	0.999
QuantityArray/broadcasting/multi_normal_array	0.0497 ± 0.00038 ms	0.0496 ± 0.0023 ms	1
QuantityArray/broadcasting/multi_quantity_array	0.053 ± 0.00029 ms	0.053 ± 0.00026 ms	1
QuantityArray/broadcasting/x^2_array_of_quantities	16.3 ± 4.5 μs	14.2 ± 3.8 μs	1.15
QuantityArray/broadcasting/x^2_normal_array	2.54 ± 2.3 μs	2.8 ± 2.6 μs	0.91
QuantityArray/broadcasting/x^2_quantity_array	6.51 ± 0.17 μs	6.53 ± 0.46 μs	0.997
QuantityArray/broadcasting/x^4_array_of_quantities	0.0812 ± 0.00076 ms	0.0813 ± 0.0063 ms	0.999
QuantityArray/broadcasting/x^4_normal_array	0.0466 ± 0.00019 ms	0.0466 ± 0.00021 ms	1
QuantityArray/broadcasting/x^4_quantity_array	0.0467 ± 0.0002 ms	0.0468 ± 0.0031 ms	0.997
time_to_load	0.207 ± 0.0066 s	0.203 ± 0.0077 s	1.02

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).

[MilesCranmer]

Does the deploydocs call later in the file (two of them) also need a GitHub object for consistency? I'm assuming the repo kwarg takes the same type?

[abhro]

It seems deploydocs() is asking for a string for repo= rather than a GitHub object (https://documenter.juliadocs.org/stable/lib/public/#Documenter.deploydocs)