## What changes were proposed in this pull request?

Remove `spark.driver.memory`, `spark.executor.memory`,  `spark.driver.cores`, and `spark.executor.cores` from `running-on-yarn.md` as they are not Yarn-specific, and they are also defined in`configuration.md`.

## How was this patch tested?
Build passed & Manually check.

Author: Weiqing Yang <yangweiqing001@gmail.com>

Closes #15869 from weiqingy/yarnDoc.

(cherry picked from commit a3cac7bd)
Signed-off-by: Sean Owen <sowen@cloudera.com>