RFR: 8356822: Refactor HTML anchor tags to javadoc in Charset

[Naoto Sato]

Simple cleanup

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Commit messages:
 - initial commit

Changes: https://git.openjdk.org/jdk/pull/25216/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25216&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8356822
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/25216.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25216/head:pull/25216

PR: https://git.openjdk.org/jdk/pull/25216