Suggestions to use system LLVM link to a section that no longer exists

[asquared31415]

At the bottom of Getting Started - Configuring the compiler there is a sentence about using the system LLVM that includes a link that would have previously had instructions on how to set that up.

You may also want to set up system LLVM to avoid building LLVM from source.

Additionally, Adding a new target - Specifying a new LLVM contains a link to the same page, suggesting

If you have a local LLVM checkout that is already built, you may be able to configure Rust to treat your build as the system LLVM to avoid redundant builds.

The section linked was removed in #1030 and the link now simply points to the top of the page for Suggested Workflows. From the content of #1030 I believe that the suggestion to use the system LLVM should be removed entirely in favor of downloading CI LLVM.