message: [doc/manifest] Add build-dependencies to Dependency sections list
  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:
diff: @@ -220,8 +220,8 @@ assets = "path/to/static"
  # 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
  