Add NullClaw logo to official Agent Skills client list

[jonathanhefner]

The Agent Skills standard site (agentskills.io) just added a clients page listing clients that support skills. It would be great to have NullClaw included on that page. Is that something NullClaw maintainers would be interested in?

[DonPrus]

Yes, it will be interesting

[jonathanhefner]

If maintainers are interested in NullClaw being listed on the Agent Skills clients page, PRs to https://github.com/agentskills/agentskills are welcome (see the contributing guide)!