SVG viewers center each <textPath> glyph on its midpoint on the path and
turn it to follow the path, which is how the Rainbow effect draws. Type on
a path with any other effect and no spacing was written as a plain
<textPath>, so a viewer drew it as Rainbow. It is now written as outlines
with a warning, as type with an end bracket, Align to Path or Spacing
already is.
Docs: docs/mcp.md, docs/target-app-parity.md.