Link the API reference from the README and back again

README.md

@@ -7,6 +7,10 @@ A multi-platform C99 utility library that exposes common building blocks — col
 [![Language: C99](https://img.shields.io/badge/Language-C99-blue.svg)](https://en.wikipedia.org/wiki/C99)
 [![Build System: CMake](https://img.shields.io/badge/Build-CMake%20%E2%89%A5%203.10-064F8C.svg)](https://cmake.org/)
 [![Platforms](https://img.shields.io/badge/Platforms-Linux%20%7C%20macOS%20%7C%20Windows-lightgrey.svg)](#requirements)
+[![API reference](https://img.shields.io/badge/docs-API%20reference-brightgreen.svg)](https://xcomart.github.io/libcmutils/api/)
+
+📖 **[API reference](https://xcomart.github.io/libcmutils/api/)** — every type and method, grouped by
+subject. This page is the guided tour; that one is the lookup.
 
 ---
 
@@ -1116,14 +1120,19 @@ of them bind ports or reach the network.
 
 ## API reference
 
-The sections above are prose. The generated reference is the same API organized for lookup — grouped
-by subject, built from the doc comments in `src/libcmutils.h`:
+**<https://xcomart.github.io/libcmutils/api/>**
+
+The sections above are prose. The reference is the same API organized for lookup — every type and
+method grouped into eighteen subjects, generated from the doc comments in `src/libcmutils.h` and
+rebuilt on every push that touches them.
+
+To build it locally instead:
 
 ```bash
 cd doc && doxygen          # or: cmake --build build --target docs
 ```
 
-Open `doc/html/index.html`. See [doc/README.md](doc/README.md) for what the topics contain.
+That writes `doc/html/index.html`. See [doc/README.md](doc/README.md) for what the topics contain.
 
 ## Project structure
 

doc/README.md

@@ -1,5 +1,9 @@
 # API reference
 
+**Published at <https://xcomart.github.io/libcmutils/api/>**, rebuilt by the
+`Docs` workflow on every push that touches the header, this directory, the
+README or the Jekyll config.
+
 The reference is generated from the doc comments in
 [`src/libcmutils.h`](../src/libcmutils.h), which is the whole public API — the
 `.c` files are implementation and are deliberately left out.

src/libcmutils.h

@@ -73,9 +73,18 @@ SOFTWARE.
  *
  * @section mp_where Where to look
  *
- * The <b>Modules</b> list groups the API by subject. The project README
- * covers the same ground in prose, and @c samples/ holds one annotated
- * program per subject.
+ * <b>Topics</b>, in the bar above, groups the API by subject - start there
+ * if you know roughly what you need. <b>Data Structures</b> lists the object
+ * types, and the search box finds anything by name.
+ *
+ * Elsewhere:
+ *
+ * - <a href="https://xcomart.github.io/libcmutils/">Project page</a> - the
+ *   same API in prose, with the reasoning behind the conventions.
+ * - <a href="https://github.com/xcomart/libcmutils">Repository</a> - source,
+ *   issues and releases.
+ * - <a href="https://github.com/xcomart/libcmutils/tree/master/samples">
+ *   Samples</a> - one annotated, runnable program per subject.
  */
 
 #ifndef LIBCMUTILS_H__