[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 (#77, #91)
  • point melange and melange-playground packages to a branch that contains the playground building scripts / changes, see diff https://github.com/melange-re/melange/compare/1.0.0...1.0.0-playground and relevant commit 064788a598bad23f95a3fe425ffba2a809c82633
  • point reason-react to the released version 0.11.0 (see same commit 064788a598bad23f95a3fe425ffba2a809c82633).
• Odoc generation:
  • backport PR #98
  • fix links (see d803be786006082c515008ac59149a9c166e1c0a)

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 https://github.com/melange-re/melange-re.github.io/commit/b2d5138).

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