RFR: JDK-8276800 Fix table headers in NumericShaper.html [v2]

[Ludvig Janiuk]

> This change introduces no visual difference, but improves a11y.

Ludvig Janiuk has updated the pull request incrementally with one additional commit since the last revision:

  Achieve correct row headers without header change

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6291/files
  - new: https://git.openjdk.java.net/jdk/pull/6291/files/71f26cd7..acc9edec

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6291&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6291&range=00-01

  Stats: 10 lines in 1 file changed: 0 ins; 0 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6291.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6291/head:pull/6291

PR: https://git.openjdk.java.net/jdk/pull/6291