[clang-tools-extra] [clang-doc] Allow setting a base directory for hosted pages (PR #132482)

[Paul Kirth via cfe-commits]

ilovepi wrote:

### Merge activity

* **Mar 28, 3:48 PM EDT**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/132482).


https://github.com/llvm/llvm-project/pull/132482