RFR: 8370071: Clarify jcmd Thread.print help message [v2]

[Sean Coffey]

> Simple tweak to jcmd Thread.print help message
> 
> jdk_svc test group ran and green

Sean Coffey has updated the pull request incrementally with one additional commit since the last revision:

  man page and better help messages

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/27861/files
  - new: https://git.openjdk.org/jdk/pull/27861/files/b7c0a1ba..4d2e42aa

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27861&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27861&range=00-01

  Stats: 9 lines in 2 files changed: 4 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/27861.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27861/head:pull/27861

PR: https://git.openjdk.org/jdk/pull/27861