Before opening a new PR, check if one already exists for the same thing

[BarsatZulkarnine]

Not a criticism of anyone - the response to this project has been incredible and the contributions are genuinely good. But looking at the open PRs right now there are some clear duplicate clusters that are making Felix's life harder than it needs to be:

• pip/venv install failures in Cookbook: at least 5 open PRs (#615, #655, #679, #723, #745)
• Document deep links: 3 PRs (#610, #631, #637)
• Emoji shortcodes: 3 PRs (#425, #432, #629)
• SSRF fixes: 3 PRs (#576, #734, #775)
• Webhook auth: 2 PRs (#640, #643)
• Accessibility: 2 PRs (#699, #738)

Each of those is Felix having to read multiple implementations of the same fix, figure out which one is better, and deal with merge conflicts after picking one. That compounds fast at 150+ open PRs.

The most useful thing most of us can do right now is probably not open another PR. It's go review the ones already open. Leave a comment, test it locally, flag a bug, approve it if it looks good. A PR that sits unreviewed helps nobody. A reviewed PR can actually get merged.

Before opening anything new, worth spending 10 minutes searching open PRs for the same issue. If one exists, review it and leave a comment rather than opening a parallel one.