update docs to have system prefix in select() examples

[rblumer4]

To do a SELECT on system types (and other system resources), you have to prefix the name with "system.", e.g.

• select("system.types", ....)

This was changed in the server a year or more ago, and fixed in the Java SDK tests 3 months ago.
But not in the docs api.md and README.md
One of the examples of deleteOne() requires "system.types", too.

Note that some interfaces still require just "types", like publish() and subscribe()
And the examples use the SystemResource enum in both places, but that will no longer work.

So also need to fix all the examples that will no longer work with SystemResources.XX.value()
OR make a SystemResource object that encapsulates both the short-name or long-name and update the examples to use that...