fix: use --cfg docsrs for document

[AsakuraMizu]

This is an alternative to #26, applying the idea described in #26 (comment).

[Copilot]

Pull request overview

This PR transitions from using --cfg doc to --cfg docsrs for documentation builds on docs.rs, following Rust's standard practice for conditional compilation during documentation generation. The change adds support for both doc and docsrs cfg flags in module definitions to ensure compatibility.

Key Changes:

• Updates Cargo.toml files to use rustc-args = ["--cfg", "docsrs"] for docs.rs metadata and enables all-features
• Adds docsrs alongside doc in conditional compilation attributes for architecture-specific modules
• Adds #[cfg_attr(doc, doc(cfg(...)))] annotations to show platform-specific availability in documentation
• Updates CI workflow to use --cfg docsrs for documentation builds

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
page_table_entry/Cargo.toml	Updates docs.rs configuration to use docsrs flag and enables all features; adds docsrs to conditional dependencies
page_table_entry/src/arch/mod.rs	Adds docsrs to cfg conditions and adds doc(cfg(...)) attributes for platform documentation
page_table_multiarch/Cargo.toml	Updates docs.rs configuration to use docsrs flag and enables all features
page_table_multiarch/tests/alloc_tests.rs	Adds cfg attributes to architecture-specific tests (but missing docsrs flag)
.github/workflows/ci.yml	Updates doc job to use docsrs flag; adds comment for test workaround
Cargo.lock	Updates dependency versions (bit_field, bitflags, log, memory_addr, rand, rustversion, x86_64)

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[AsakuraMizu]

Note that the line #[cfg_attr(doc, doc(cfg(target_arch = "x86_64")))] is required; otherwise, the generated document will display the module x86_64 as "Available on x86-64 or docsrs only."

[AsakuraMizu]

The "dirty trick" mentioned in #26 (comment) does not work since the quote issue described in #25.

[Azure-stars]

LGTM.