Clarify the behavior of `append` for a `null` `CharSequence` parameter and clean up a couple of other typos.
------------- Commit messages: - 8328183: Minor mistakes in docs of PrintStream.append() Changes: https://git.openjdk.org/jdk/pull/18607/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18607&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8328183 Stats: 17 lines in 5 files changed: 5 ins; 1 del; 11 mod Patch: https://git.openjdk.org/jdk/pull/18607.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/18607/head:pull/18607 PR: https://git.openjdk.org/jdk/pull/18607
