Match CI doc testing with docs.rs. (#157)

* Remove `-Zunstable-options -Zrustdoc-scrape-examples` from CI. It
wasn't even enabled for docs.rs and we don't have any examples by
Cargo's definition, so not worth enabling scraping at this point.
* Treat doc warnings as errors. Historically we've not done so due to
various `rustdoc` bugs giving false positives but I got it to pass
without failure right now, so perhaps better times have arrived.
* Pass `--all-features` at docs.rs to match our CI and reduce the
maintenance burden of manually syncing the features list.
* Enable the `doc_auto_cfg` feature for docs.rs which will show a little
tip next to feature gated functionality informing of the crate feature
flag.

.github/workflows/ci.yml

@@ -247,15 +247,17 @@ jobs:
         with:
           save-if: ${{ github.event_name != 'merge_group' }}
 
-      # We test documentation using nightly to match docs.rs. This prevents potential breakages
+      # We test documentation using nightly to match docs.rs.
       - name: cargo doc
-        run: cargo doc --workspace --locked --all-features --no-deps --document-private-items -Zunstable-options -Zrustdoc-scrape-examples
+        run: cargo doc --workspace --locked --all-features --no-deps --document-private-items
+        env:
+          RUSTDOCFLAGS: '--cfg docsrs -D warnings'
 
-  # If this fails, consider changing your text or adding something to .typos.toml
+  # If this fails, consider changing your text or adding something to .typos.toml.
   typos:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
 
       - name: check typos
-        uses: crate-ci/typos@v1.26.0
+        uses: crate-ci/typos@v1.27.0

examples/vello_editor/Cargo.toml

@@ -5,6 +5,7 @@ edition.workspace = true
 rust-version.workspace = true
 license.workspace = true
 repository.workspace = true
+publish = false
 
 [dependencies]
 vello = "0.3.0"

parley/Cargo.toml

@@ -9,6 +9,9 @@ rust-version.workspace = true
 license.workspace = true
 repository.workspace = true
 
+[package.metadata.docs.rs]
+all-features = true
+
 [lints]
 workspace = true
 

parley/src/lib.rs

@@ -72,6 +72,7 @@
 //! }
 //! ```
 
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 // TODO: Remove this dead code allowance and hide the offending code behind the std feature gate.
 #![cfg_attr(not(feature = "std"), allow(dead_code))]
 #![cfg_attr(all(not(feature = "std"), not(test)), no_std)]