feat: add setup API

[ph-fritsche]

What:

Add a setup API

Why:
Closes #743

How:

userEvent.setup(defaultOptions) returns the APIs of userEvent bound to default options.
It also reapplies keyboardState to subsequent calls of keyboard().

The returned object also includes a setup() function that returns a set of APIs with other overwritten defaults but the same keyboardState.

Checklist:

• Documentation
• Tests
• Ready to be merged

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[codecov]

Codecov Report

Merging #746 (13bab99) into userEvent14 (9519979) will not change coverage.
The diff coverage is 100.00%.

@@              Coverage Diff              @@
##           userEvent14      #746   +/-   ##
=============================================
  Coverage       100.00%   100.00%           
=============================================
  Files               50        51    +1     
  Lines              965      1032   +67     
  Branches           389       411   +22     
=============================================
+ Hits               965      1032   +67     

Impacted Files	Coverage Δ
src/tab.ts	100.00% <ø> (ø)
src/upload.ts	100.00% <ø> (ø)
src/index.ts	100.00% <100.00%> (ø)
src/keyboard/index.ts	100.00% <100.00%> (ø)
src/setup.ts	100.00% <100.00%> (ø)
src/click.ts	100.00% <0.00%> (ø)
src/type/index.ts	100.00% <0.00%> (ø)
src/select-options.ts	100.00% <0.00%> (ø)
... and 7 more

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