[DO NOT MERGE] 1.0.0 patches

[jchavarri]

This branch is not for merging purposes, just used as a way to apply changes to the v1.0.0 version.

We are backporting:

• The playground, which means:
  • reapplying the PRs where the playground was added (Scaffold mockup for the playground #77, playground: deploy #91)
  • point melange and melange-playground packages to a branch that contains the playground building scripts / changes, see diff melange-re/melange@1.0.0...1.0.0-playground and relevant commit 064788a
  • point reason-react to the released version 0.11.0 (see same commit 064788a).
• Odoc generation:
  • backport PR odoc: publish melange docs and link to them from the docs articles #98
  • fix links (see d803be7)

The v1.0.0 tag was changed to point to the most recent commit in this PR so that mike publication ci job can kick in (before it was pointing to b2d5138).

We might want to keep this branch around in case we need to reapply other patches from master.