RFR: 8292566: Add reference to the java.nio.file package in java.nio package documentation [v2]

[Brian Burkhalter]

> Add a phrase about `java.nio.file` to the sentence in the `java.nio` package documentation describing its subpackages.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8292566: Expand list of central abstractions; refine previous addition; update copyright year

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Changes:
  - all: https://git.openjdk.org/jdk/pull/9910/files
  - new: https://git.openjdk.org/jdk/pull/9910/files/b7279eb9..53cdc086

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9910&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9910&range=00-01

  Stats: 21 lines in 1 file changed: 17 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/9910.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9910/head:pull/9910

PR: https://git.openjdk.org/jdk/pull/9910