Add cargo doc to CI

This was present in the travis configuration that was removed in f3c5f88. It remains useful since it can catch errors in the rustdoc such as in https://travis-ci.org/github/mozilla/mp4parse-rust/jobs/774702058

Author: baumanj

.github/workflows/build.yml

@@ -62,6 +62,13 @@ jobs:
       run: rustup run ${{ matrix.rust }} cargo test --all --verbose
       if: ${{ !matrix.release }}
 
+    - name: Doc (release)
+      shell: bash
+      run: rustup run ${{ matrix.rust }} cargo doc --document-private-items
+      env:
+        RUSTDOCFLAGS: "-Dwarnings"
+      if: matrix.release
+
     # cargo-fuzz supports x86-64 Linux and x86-64 macOS, but macOS currently fails, see:
     # https://github.com/mozilla/mp4parse-rust/pull/210#issuecomment-597420191
     - name: Install cargo-fuzz

mp4parse/src/lib.rs

@@ -483,7 +483,7 @@ pub struct VPxConfigBox {
     pub codec_init: TryVec<u8>,
 }
 
-/// See AV1-ISOBMFF § 2.3.3 https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax
+/// See [AV1-ISOBMFF § 2.3.3](https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax)
 #[derive(Debug)]
 pub struct AV1ConfigBox {
     pub profile: u8,
@@ -502,7 +502,6 @@ pub struct AV1ConfigBox {
 }
 
 impl AV1ConfigBox {
-    /// See https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax
     const CONFIG_OBUS_OFFSET: usize = 4;
 
     pub fn config_obus(&self) -> &[u8] {
@@ -3733,7 +3732,7 @@ fn read_vpcc<T: Read>(src: &mut BMFFBox<T>) -> Result<VPxConfigBox> {
     })
 }
 
-/// See AV1-ISOBMFF § 2.3.3 https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax
+/// See [AV1-ISOBMFF § 2.3.3](https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax)
 fn read_av1c<T: Read>(src: &mut BMFFBox<T>) -> Result<AV1ConfigBox> {
     // We want to store the raw config as well as a structured (parsed) config, so create a copy of
     // the raw config so we have it later, and then parse the structured data from that.
@@ -4124,7 +4123,7 @@ fn read_esds<T: Read>(src: &mut BMFFBox<T>) -> Result<ES_Descriptor> {
 }
 
 /// Parse `FLACSpecificBox`.
-/// See https://github.com/xiph/flac/blob/master/doc/isoflac.txt §  3.3.2
+/// See [Encapsulation of FLAC in ISO Base Media File Format](https://github.com/xiph/flac/blob/master/doc/isoflac.txt) §  3.3.2
 fn read_dfla<T: Read>(src: &mut BMFFBox<T>) -> Result<FLACSpecificBox> {
     let (version, flags) = read_fullbox_extra(src)?;
     if version != 0 {