chore(docs): make docs working in IE11

[layershifter]

Update Prettier and use core-js

Even previous version of Prettier uses .trimRight() which was not covered by existing version of @babel/polyfill. @babel/polyfill is deprecated so it was replaced with core-js as suggested.

Compile more dev deps

Should also include leven and chalk to compiled dependencies because they contain arrow functions which are not supported by IE11.

Use Terser only for prod

In #3652 switched minifier to Terser, but by mistake it was applied even for dev builds. Fixed 🔨

[codecov-io]

Codecov Report

Merging #3678 into master will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3678      +/-   ##
==========================================
+ Coverage   99.81%   99.83%   +0.02%     
==========================================
  Files         174      174              
  Lines        2755     3100     +345     
==========================================
+ Hits         2750     3095     +345     
  Misses          5        5

Impacted Files	Coverage Δ
src/modules/Transition/TransitionGroup.js	100% <0%> (ø)	⬆️
src/addons/Ref/RefFindNode.js	100% <0%> (ø)	⬆️
src/addons/Pagination/Pagination.js	100% <0%> (ø)	⬆️
src/addons/Pagination/PaginationItem.js	100% <0%> (ø)	⬆️
src/modules/Modal/Modal.js	100% <0%> (ø)	⬆️
src/addons/Confirm/Confirm.js	100% <0%> (ø)	⬆️
src/modules/Accordion/AccordionAccordion.js	100% <0%> (ø)	⬆️
src/modules/Checkbox/Checkbox.js	100% <0%> (ø)	⬆️
src/modules/Sidebar/Sidebar.js	100% <0%> (ø)	⬆️
src/elements/List/List.js	100% <0%> (ø)	⬆️
... and 36 more

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