doc: better chameleon notes

src/chameleon/README.md

@@ -1,12 +1,26 @@
 # Chameleon
 
-Given a `yaml` action function specification, `chameleon` generates:
-- language bindings
-- action function tests, for all languages
+Chameleon is a code generator. Given a `yaml` action function specification,
+a file named `Action.yaml` in an algorithm's source code directory, Chameleon
+generates:
 
-`chameleon` is run automatically by `meson` at build-time; all generated
-code is produced in the build tree. If you want to test `chameleon`, you
-may also run it locally:
+| Language | Bindings                 | Tests                    |
+| ---      | ---                      | ---                      |
+| Fortran  | :heavy_check_mark:       | :heavy_multiplication_x: |
+| Java     | :heavy_multiplication_x: | :heavy_multiplication_x: |
+| Python   | :heavy_multiplication_x: | :heavy_multiplication_x: |
+
+where
+- :heavy_check_mark: means fully supported (as long as the algorithm has an `Action.yaml` file)
+- :heavy_multiplication_x: means this is not _yet_ supported
+
+The main script is [`chameleon`](chameleon). For usage, run
 ```bash
 chameleon --help
 ```
+There is no need to run `chameleon` yourself unless you are developing or debugging it.
+`chameleon` is run automatically by `meson` at build time and all generated
+code is produced in the build tree at
+```
+src/iguana/algorithms/chameleon_*
+```