Move timex docs to the top of the file

[leedm777]

Move the docs for the supported timex exporter above the docs of the deprecated ntp module. Many folks see the word "deprecated" and stop reading without realizing there's a supported option buried at the bottom of the file.

@SuperQ / @discordianfish

[SuperQ]

This needs a DCO sign-off. You can use git commit -s --amend to add it.

[leedm777]

@SuperQ I corrected the DCO sign-off. Thanks.