instr-runtime-node is missing from docs' list of included instrumentations

https://www.elastic.co/docs/reference/opentelemetry/edot-sdks/nodejs/supported-technologies#instrumentations

instr-runtime-node should be in ^^ that table.

(Aside: I wonder if we could revive a sort of bitrot.js that could catch these things. More difficult with docs and code in separate repos, though.)