The `[build-dependencies]` section was missing from the Dependency
sections list, making it hard to find its existence and link to
`specifying-dependencies` page. This puts the section title in the list,
so a normal find works.
Background: https://github.com/rust-lang/cargo/issues/4309#issuecomment-
317965620
# Dependency sections
See the [specifying dependencies page](specifying-dependencies.html) for
-information on the `[dependencies]`, `[dev-dependencies]`, and target-specific
-`[target.*.dependencies]` sections.
+information on the `[dependencies]`, `[dev-dependencies]`,
+`[build-dependencies]`, and target-specific `[target.*.dependencies]` sections.
# The `[profile.*]` sections