feat(docs): make prototypes conditionally public

[lucivpav]

This PR contains several changes to the docs site:

1. Prototypes section moved below Behaviors.
2. Each prototype has a public flag, which determines whether the prototype should be visible in Prod build.
3. Custom Styled Toolbar is public.

In non-Prod build:

In Prod build:

This PR should be merged after #1611.

[codecov]

Codecov Report

Merging #1627 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1627   +/-   ##
=======================================
  Coverage   71.24%   71.24%           
=======================================
  Files         851      851           
  Lines        7035     7035           
  Branches     2027     2027           
=======================================
  Hits         5012     5012           
  Misses       2017     2017           
  Partials        6        6

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