docs-files-api: headings say something

Generated-by: Claude Opus 5.5

docs-files-api/SKILL.md

@@ -17,6 +17,12 @@ A **README** sells, then gets the reader running:
   at (a URL, output). No architecture, no principles.
 - **After that:** features and benefits, as much as earns its place.
 
+**Headings say something.** A heading is prime real estate: it shows in
+the outline and in link targets. "What's in it", "Overview", "Features",
+"Details" say nothing; name the point instead ("Bookmarks in, a zine
+out"). Plain labels are fine only where the reader hunts for them by
+name: "Getting started", "Deploying".
+
 Everything else goes in **CONTRIBUTING**: design, layout of the code,
 how to test, conventions, deploying.