Direct Parameters

[teubert]

Add support to set parameters directly using square brackets in the model so that

m.parameters['abc'] = 1

becomes

m['abc'] = 1

Also updated the examples to take advantage of this feature.

.parameters syntax will still work as expected (and be slightly faster), but this provides a cleaner syntax for parameters.

[github-actions]

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[kjjarvis]

Change to direct access to parameters looks good