support relative paths when configuring jdk

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my project's jdk is located in a directory relative to the project root, but specifying a relative path does not seem to be supported:

{
    "java.jdt.ls.java.home": "./jdk"
    // also doesn't work:
    // "java.jdt.ls.java.home": "${workspaceFolder}/jdk"
}

it would be nice if i could do this because it would allow me to commit this in my workspace settings.json so that others working on my project don't have to configure the path to their jdk manually, since it's located in the same spot for everybody