docs: add TweetClaw companion workflow

[kriptoburak]

Summary:

• add a short README section for pairing Now4real site chat with TweetClaw when the same OpenClaw agent needs X/Twitter workflows
• include the canonical npm OpenClaw install command for TweetClaw
• keep Now4real scoped to website chat, webhooks, and chatbot replies while TweetClaw handles X/Twitter jobs and approval-sensitive actions

Validation:

• git diff --check
• package.json and openclaw.plugin.json parse
• npm view @xquik/tweetclaw version openclaw.install --json
• README link check, with documented placeholder/API-root URLs classified separately
• npm ci --ignore-scripts --no-audit --no-fund
• npm run build

Disclosure: I maintain Xquik and built the TweetClaw plugin.