RFR: 8261673: Move javadoc for the lookup mechanism to module-info [v2]

[Joe Wang]

> Consolidate and move javadoc for the lookup mechanism to the module summary.

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

  Fix typos: s/XMLEventFactory/XMLInputFactory s/XMLEventFactory/XMLOutputFactory

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3020/files
  - new: https://git.openjdk.java.net/jdk/pull/3020/files/9884e8ce..5554c8df

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3020&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3020&range=00-01

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3020.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3020/head:pull/3020

PR: https://git.openjdk.java.net/jdk/pull/3020