[50 MRG] Feature: CSS variable theme tokens export

[TUPM96]

50 MRG

Export design tokens JSON from generated theme.

Acceptance

• Docs

Claim (MergeOS MRG)

1. Follow https://github.com/mergeos-bounties
2. Star https://github.com/mergeos-bounties/mergeos
3. Star https://github.com/mergeos-bounties/mergeos-contracts
4. Comment on this issue: I claim this bounty
5. Comment on MergeOS Claim Token #1 with this issue link
6. Open a PR to BloggerEasy default branch with Fixes #<n>

Payout

Maintainer review → merge → MRG credit 25 / 50 / 100 / 200 only.

[CloneBro]

I claim this bounty

PR: #90