Replace Pipelines "Behind the Scenes" with "Result Display Rendering"

The previous "Behind the Scenes" docs has some problems:

* The title is not descriptive
* Confusing context reference: The "You may have wondered" references `ls` output despite no applicable example in front of it - and is not stable against other docs section changes either way
* Confusing false equivalence: Claims "one and the same" and then explains how they are not in fact the same

The section is being replaced with a "Result Display Rendering", which

* Mentions and explains the existence of a display output hook
* Begins with establishing context: The section is about interactive shell pipeline result display output

---

I kept the section small as not to duplicate content from the Hooks documentation page.

Adding examples for current, different, or simplified displaying may be reasonable here, but would duplicate the hooks "Changing how Output is Displayed" and "Filtering or Diverting Command Output" sections.

Author: Kissaki

book/pipelines.md

@@ -353,34 +353,10 @@ In this case, sleep takes `nothing` and instead expects an argument.
 So, we can supply the output of the `echo` command as an argument to it:
 `echo 1sec | sleep $in` or `sleep (echo 1sec)`
 
-## Behind the Scenes
+## Result Display Rendering
 
-You may have wondered how we see a table if [`ls`](/commands/docs/ls.md) is an input and not an output. Nu adds this output for us automatically using another command called [`table`](/commands/docs/table.md). The [`table`](/commands/docs/table.md) command is appended to any pipeline that doesn't have an output. This allows us to see the result.
-
-In effect, the command:
-
-```nu
-> ls
-```
-
-And the pipeline:
-
-```nu
-> ls | table
-```
-
-Are one and the same.
-
-::: tip Note
-The phrase _"are one and the same"_ above only applies to the graphical output in the shell, it does not mean the two data structures are the same:
-
-```nushell
-(ls) == (ls | table)
-# => false
-```
-
-`ls | table` is not even structured data!
-:::
+In interactive mode, when a pipeline ends, the [`display_output` hook configuration](hooks.md#changing-how-output-is-displayed) defines how the result will be displayed.
+The default configuration uses the [`table` command](/commands/docs/table.md) to render structured data as a visual table.
 
 ## Output Result to External Commands