ci: Update and embed docs in one step using generator.py

`generator.py` can now be used to perform documentation generation and
embedding in one go, simplifying the entire process while at the same
time getting rid of intermediate `docs.md` being checked in to the
repository.  For this the CI needs the submodules with `gir` and the
`.gir` files.

.gitlab-ci.yml

@@ -443,29 +443,33 @@ coverage:
       cobertura: coverage.xml
 
 docs:
+  variables:
+    GIT_SUBMODULE_STRATEGY: recursive
   extends: .img-nightly
   stage: 'extras'
   script:
+    - cargo install rustdoc-stripper
+    - PATH=~/.cargo/bin/:$PATH ./generator.py --embed-docs --no-fmt
     - |
-      for crate in gstreamer* gstreamer-gl/{egl,wayland,x11}; do
-        pushd $crate
-        RUSTDOCFLAGS="$RUST_DOCS_FLAGS" cargo +nightly doc --color=always --features=dox,embed-lgpl-docs --no-deps
-        popd
-      done
-
-pages:
-  extends: .img-nightly
-  stage: 'deploy'
-  
-  script:
-    - |
-      for crate in gstreamer* gstreamer-gl/{egl,wayland,x11}; do
-        cd $crate
-        RUSTDOCFLAGS="$RUST_DOCS_FLAGS" cargo +nightly doc --color=always --features=dox,embed-lgpl-docs --no-deps
-        cd ..
-      done
+      crate_names=$(for manifest in gstreamer*/Cargo.toml; do echo -n " -p ${manifest%%/Cargo.toml}"; done)
+      crate_names="$crate_names -p gstreamer-gl-egl -p gstreamer-gl-wayland -p gstreamer-gl-x11"
+      RUSTDOCFLAGS="$RUST_DOCS_FLAGS" cargo +nightly doc $crate_names --color=always --features=dox --no-deps
     - mv target/doc public/
-  when: 'manual'
+  artifacts:
+    paths:
+      - 'public'
+
+# https://docs.gitlab.com/ee/user/project/pages/#how-it-works
+# GitLab automatically deploys the `public/` folder from an
+# artifact generated by the job named `pages`.  This step
+# re-uses the docs from the build-test `docs` step above.
+pages:
+  stage: 'deploy'
+  when: 'manual'
+  dependencies:
+    - docs
+  script:
+    - ls public/
   artifacts:
     paths:
       - 'public'