Don't recommend setting html_root_url

Author: jyn514

src/checklist.md

@@ -36,7 +36,6 @@
   - [ ] Cargo.toml includes all common metadata ([C-METADATA])
     - authors, description, license, homepage, documentation, repository,
       readme, keywords, categories
-  - [ ] Crate sets html_root_url attribute "https://docs.rs/CRATE/X.Y.Z" ([C-HTML-ROOT])
   - [ ] Release notes document all significant changes ([C-RELNOTES])
   - [ ] Rustdoc does not show unhelpful implementation details ([C-HIDDEN])
 - **Predictability** *(crate enables legible code that acts how it looks)*

src/documentation.md

@@ -202,51 +202,6 @@ crate other than the source repository or API documentation. Do not make
 `homepage` redundant with either the `documentation` or `repository` values. For
 example, serde sets `homepage` to *https://serde.rs*, a dedicated website.
 
-[C-HTML-ROOT]: #c-html-root
-<a id="c-html-root"></a>
-### Crate sets html_root_url attribute (C-HTML-ROOT)
-
-<!--
-Remove this guideline once rustdoc links no-deps documentation with no
-html_root_url to docs.rs by default.
-https://github.com/rust-lang/rust/issues/42301
--->
-
-It should point to `"https://docs.rs/CRATE/MAJOR.MINOR.PATCH"`,
-assuming the crate uses docs.rs for its primary API documentation.
-
-The `html_root_url` attribute tells rustdoc how to create URLs to
-items in the crate when compiling downstream crates. Without it, links
-in the documentation of crates that depend on your crate will be
-incorrect.
-
-```rust
-#![doc(html_root_url = "https://docs.rs/log/0.3.8")]
-```
-
-Because this URL contains an exact version number, it must be kept in
-sync with the version number in `Cargo.toml`. The [`version-sync`]
-crate can help with this by letting you add an integration test that
-fails if the `html_root_url` version number is out of sync with the
-crate version.
-
-[`version-sync`]: https://crates.io/crates/version-sync
-
-If you do not like that mechanism, it is recommended to add a comment
-to the `Cargo.toml` version key reminding yourself to keep the two
-updated together, like:
-
-```toml
-version = "0.3.8" # remember to update html_root_url
-```
-
-For documentation hosted outside of docs.rs, the value for `html_root_url` is
-correct if appending the crate name + index.html takes you to the documentation
-of the crate's root module. For example if the documentation of the root module
-is located at `"https://api.rocket.rs/rocket/index.html"` then the
-`html_root_url` would be `"https://api.rocket.rs"`.
-
-
 <a id="c-relnotes"></a>
 ## Release notes document all significant changes (C-RELNOTES)