fix typo

Author: pfitzseb

README.md

@@ -51,6 +51,6 @@ MultiDocumenter.make(
 
 Check [`.github/workflows/deploy.yml`](.github/workflows/deploy.yml) and [`docs/make.jl`](docs/make.jl) for an example on how to deploy MultiDocumenter-generated aggregates to a git branch.
 
-The result of that script as available at [https://juliacomputing.github.io/MultiDocumenter.jl/](https://juliacomputing.github.io/MultiDocumenter.jl/).
+The result of that script is available at [https://juliacomputing.github.io/MultiDocumenter.jl/](https://juliacomputing.github.io/MultiDocumenter.jl/).
 
 You can of course also just push the output artefact directly to S3 or some other hosting service.