RFR: 8321573: Improve Platform.Preferences documentation [v2]

[Michael Strauß]

> This PR enhances the documentation of `Platform.Preferences.accentColor`:
> 
> 
>    /**
> -   * The accent color.
> +   * The accent color, which can be used to highlight the active or important part of a
> +   * control and make it stand out from the rest of the user interface. It is usually a
> +   * vivid color that contrasts with the foreground and background colors.
> 
> 
> Additional changes include alternating row colors for tables.

Michael Strauß has updated the pull request incrementally with one additional commit since the last revision:

  wording, table styling

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1301/files
  - new: https://git.openjdk.org/jfx/pull/1301/files/89858a90..c1e78a04

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1301&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1301&range=00-01

  Stats: 22 lines in 1 file changed: 9 ins; 1 del; 12 mod
  Patch: https://git.openjdk.org/jfx/pull/1301.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1301/head:pull/1301

PR: https://git.openjdk.org/jfx/pull/1301