Update README.md with note about test failures on Windows (#1848)

README.md

@@ -28,6 +28,9 @@ Then, build using using Maven:
 mvn clean package appassembler:assemble
 ```
 
+Note that on Windows, tests may fail due to encoding issues, see [#1466](https://github.com/castorini/anserini/issues/1466).
+Solution is to skip tests by adding `-Dmaven.test.skip=true` to the above `mvn` command.
+
 The `tools/` directory, which contains evaluation tools and other scripts, is actually [this repo](https://github.com/castorini/anserini-tools), integrated as a [Git submodule](https://git-scm.com/book/en/v2/Git-Tools-Submodules) (so that it can be shared across related projects).
 Build as follows (you might get warnings, but okay to ignore):