Script processor doc links to update API examples which is confusing

[ppf2]

On this page (https://www.elastic.co/guide/en/elasticsearch/reference/master/script-processor.html), we link to the general scripting examples page that is used by the update API.

See How to use scripts to learn more about writing scripts. The Script Processor leverages caching of compiled scripts for improved performance. Since the script specified within the processor is potentially re-compiled per document, it is important to understand how script caching works. To learn more about caching see Script Caching.

This is misleading because the ingest processor context for painless is different from the update API. Users end up trying to get the update API examples working (for example, ctx._source does not work in the ingest node context).

It will be helpful to have an example page linked from script processor that is for ingest node (does not include all the examples for other non-ingest use cases of painless), or provide ingest node script processor examples directly on the script processor page. Thx!

[elasticmachine]

Pinging @elastic/es-docs (Team:Docs)

[elasticmachine]

Pinging @elastic/es-core-features (Team:Core/Features)