Improve the documentation for the Jetty Server Dump

[lachlan-roberts]

trafficstars

Improve the Jetty Server Dump documentation and split it out from troubleshooting/index.adoc to its own page which can be linked more easily.

• Split the docs for Jetty Server Dump out to its own page.
• Add initial section about dumpAfterStart from command line and embedded usages.
• operations-guide just links to the detailed Jetty Server Dump page in the programming guide so we don't duplicate these docs.

[gregw]

@lachlan-roberts status if this PR?

[sbordet]

@lachlan-roberts I'll take this over.