RFR: 8328627: JShell documentation should be clearer about "remote runtime system" [v3]

[Jan Lahoda]

> This change attempts to more clearly explain the difference between `-J` and `-R` for JShell.

Jan Lahoda has updated the pull request incrementally with one additional commit since the last revision:

  Updated as suggested.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18450/files
  - new: https://git.openjdk.org/jdk/pull/18450/files/97cd0232..6f8651dd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18450&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18450&range=01-02

  Stats: 6 lines in 2 files changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/18450.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18450/head:pull/18450

PR: https://git.openjdk.org/jdk/pull/18450