Changes:
- Add one Mqttable entry linking to its official website.
- Describe traffic inspection, replay, load testing, fault injection, and PCAP analysis without claiming an open-source license.
- Place the entry between MQTT.fx and mqttcli using the existing list marker required by the upstream linter.
Validation:
- Run npx --yes awesome-lint on the upstream baseline and final change; both pass.
- Pass Python checks for a single-entry diff, contribution structure, Tools category, alphabetical neighbors, whitespace, and final newline.
- Verify https://mqttable.com/ returns HTTP 200 with ego-browser and confirm the description against the product homepage and source README.
- Pass staged-diff secret, sensitive-file, and file-size scans and manual security review; website-specific ignore-template probes are inapplicable to this Markdown-only repository.
- Pass git diff --check and git diff --cached --check.
- Do not run an application build or runtime tests because only one Markdown list entry changes.
