feat(build): add a development entry point

[bigopon]

📖 Description

Add a "development" condition in exports to support some platforms like https://esm.sh/#docs
Those platforms that do support it will be able to pick the right dev dist.

[codecov]

Codecov Report

Merging #1770 (fe25185) into master (1c9c97c) will increase coverage by 0.02%.
The diff coverage is 96.13%.

@@            Coverage Diff             @@
##           master    #1770      +/-   ##
==========================================
+ Coverage   88.01%   88.04%   +0.02%     
==========================================
  Files         242      242              
  Lines       22555    22549       -6     
  Branches     5163     5161       -2     
==========================================
+ Hits        19852    19853       +1     
+ Misses       2703     2696       -7     

Impacted Files	Coverage Δ
packages/runtime-html/src/renderer.ts	88.52% <ø> (ø)
...me-html/src/resources/value-converters/sanitize.ts	11.11% <0.00%> (-11.12%)	⬇️
packages/runtime-html/src/utilities.ts	96.87% <ø> (-0.10%)	⬇️
packages/runtime/src/observation/dirty-checker.ts	96.72% <ø> (ø)
.../src/resources/binding-behaviors/update-trigger.ts	75.00% <75.00%> (-1.48%)	⬇️
packages/runtime-html/src/utilities-dom.ts	88.88% <85.71%> (-1.12%)	⬇️
...ntime-html/src/templating/controller.projection.ts	92.75% <87.50%> (-0.40%)	⬇️
packages/runtime-html/src/templating/children.ts	86.86% <92.85%> (+2.40%)	⬆️
packages/runtime-html/src/templating/controller.ts	88.45% <95.00%> (+0.26%)	⬆️
...ges/runtime-html/src/compiler/template-compiler.ts	97.78% <96.00%> (+0.11%)	⬆️
... and 30 more

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[3cp]

Interesting Node is still adding more and more fields into package.json.
Those fields affect module resolution. This is one of the complexities that Deno decided to get ride of from day 1.