v1.1.5 — the supporters page goes back to text only

The supporters page goes back to text only.

Tailscale's logo came off the page, and the image it pointed at is
removed with it rather than left serving at a public URL nothing links
to. All three entries — Tailscale, BrowserStack and Docker — now read the
same way: a name, a link, what the support covers, and the date it
started.

The page can still carry a logo. The rendering and the optional fields
behind it are untouched, so a supporter that supplies a mark gets one
without another change here. What is gone is the single asset, not the
capability.

The note explaining Docker's empty badge moved out of the entry and now
lives only at the top of the file, where the same explanation already
stood: Docker awards the Sponsored OSS mark on its own Hub namespace, so
there is no wording for this repository to keep true. One copy of that
reasoning is the right number.