Auto merge of #7721 - ehuss:fix-doc-build-indent, r=Eh2406
Auto merge of #7721 - ehuss:fix-doc-build-indent, r=Eh2406

Fix indentation mistake in doc comment.

The `build` directory should be under `debug`.

eminence/cargo,vojtechkral/cargo,nipunn1313/cargo,vojtechkral/cargo,tshepang/cargo,rust-lang/cargo,rustyhorde/cargo,tsurai/cargo,vojtechkral/cargo,tsurai/cargo,rustyhorde/cargo,tshepang/cargo,rustyhorde/cargo,rustyhorde/cargo,tshepang/cargo,vojtechkral/cargo,nipunn1313/cargo,tsurai/cargo,nipunn1313/cargo,rust-lang/cargo,tsurai/cargo,eminence/cargo,tshepang/cargo,nipunn1313/cargo,eminence/cargo,rust-lang/cargo,rust-lang/cargo,eminence/cargo,tsurai/cargo