Documentation for HTTPRoute Timeouts

[SRodi]

Write documentation for HTTPRoute Timeouts which relates to the following:

• implementation PR: HTTPRoute timeout #2013
• GEP-1742: HTTPRoute Timeouts
• PR to add API proposal to GEP-1742: GEP-1742: HTTPRoute Timeouts API #1997
• Use of new Duration format, see GEP-2257: Gateway API Duration Format

/cc @frankbu @robscott - you can assign this Issue to myself (I have no permission do that)

[youngnick]

/assign @SRodi

[SRodi]

closing as this was done in #2492