Document new XTS Features

Plan for new XTS features and docs:

1. Implement new feature
2. Release a milestone of 5.0.0
3. Publish a blog post shortly after release
4. Refine the feature based on community feedback
5. Document the feature in the XTS xts_administration_and_development_guide before the 5.0.0.Final release (this issue is to do this item)

Here's a list of features that need documenting, so far:

JBTM-986 Automatically setup the client side handler chain
JBTM-1447 Create WebserviceFeature for TXBridge
Bridging stuff