Update CONTRIBUTING.md with Windows SDKMan note

Added note about potential file path error on Windows during javadoc step.

Signed-off-by: Jon Bartels <jonathan.bartels@gmail.com>

Author: jonbartels

CONTRIBUTING.md

@@ -36,7 +36,7 @@ The build is driven by Gradle through the included wrapper; no separate Gradle i
 ./gradlew test                          # run the unit tests (-Dcoverage=true for JaCoCo)
 ./gradlew dist                          # build the distribution extension zips
 ```
-On Windows use `gradlew.bat` instead of `./gradlew`. The assembled distribution lands in `server/setup`, the same location the previous Ant build used. For release artifacts, run a clean build: `./gradlew clean build dist`.
+On Windows use `gradlew.bat` instead of `./gradlew`. The assembled distribution lands in `server/setup`, the same location the previous Ant build used. For release artifacts, run a clean build: `./gradlew clean build dist`. Windows with SDKMan may generate an error about the file path being too long in the javadoc step, skip this by adding `-x :server:userApiJavadoc` to your Gradle command.
 
 Dependencies are pinned and checksum-verified. To change a dependency version: edit `gradle/libs.versions.toml`, then refresh the checksum metadata **with a cold dependency cache and CI's flags**:
 ```bash