doc improvement: summarizer as transformer not summarizer

[fscelliott]

https://sensiblehq.slack.com/archives/C02EFB8TMGC/p1687285298987149

like: Use it

1. to summarize
2. to transform data that you otherwise can't using other coputed fields or custom types etc.

[fscelliott]

also update all the 'this is an alternative to list' references?

[fscelliott]

done with:

Example use cases for this method include:

• To transform another method's output when using [types](doc:types) or other [computed field methods](doc:computed-field-methods) is difficult. For example, if you use the [Row](doc:row) method to return an inconsistently formatted ranking (first, 1st, 1), then you can use this method to consistently format the ranking. For example, you can reformat with instructions like the following snippet is a ranking. Return it formatted liked \"1st\", \"2nd\", \"3rd\" and so forth, not written out like \"first\" or in digit-only format like \"1\".