RFR: 8339696: Clarify modeling scope of javax.lang.model.element [v2]

[Joe Darcy]

> Clarify that while javax.lang.model does not include an AST API, it is intended to be usable by an AST API.

Joe Darcy has updated the pull request incrementally with one additional commit since the last revision:

  Reflow paragraph.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20900/files
  - new: https://git.openjdk.org/jdk/pull/20900/files/2c213737..ac8ac995

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20900&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20900&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/20900.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20900/head:pull/20900

PR: https://git.openjdk.org/jdk/pull/20900