Nexus docs with samples for common things like signal, signal-with-start, update, mapping to multiple workflow args

[prasek]

Temporal Affiliation

• I am a Temporal employee

Content Suggestion

Update the Nexus developer guides to includes samples for common Nexus tasks, including the following:

• Nexus samples and dev guide docs for sync Nexus ops that use signal, signal-with-start, update, query, ... features#664
• Nexus samples and dev guide docs to map a Nexus Operation input to multiple Workflow arguments features#665

@Sushisource suggests we may be able to create a single Nexus example that covers all of these things and then add Nexus dev guide docs using the single example.