Table help rendering (#13182)

# Description

Mostly fixes #13149 with much of the credit to @fdncred.

This PR runs `table --expand` against `help` example results. This is
essentially the same fix that #13146 was for `std help`.

It also changes the shape of the result for the `table --expand`
example, as it was hardcoded wrong.

~Still needed is a fix for the `table --collapse` example.~ Note that
this is also still a bug in `std help` that I didn't noticed before.

# User-Facing Changes

Certain tables are now rendered correctly in the help examples for:

* `table`
* `zip`
* `flatten`
* And almost certainly others

# Tests + Formatting

- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting

---------

Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>

crates/nu-command/src/viewers/table.rs

@@ -170,7 +170,10 @@ impl Command for Table {
                     }),
                     Value::test_record(record! {
                         "a" =>  Value::test_int(3),
-                        "b" =>  Value::test_int(4),
+                        "b" =>  Value::test_list(vec![
+                            Value::test_int(4),
+                            Value::test_int(4),
+                        ])
                     }),
                 ])),
             },
@@ -184,7 +187,10 @@ impl Command for Table {
                     }),
                     Value::test_record(record! {
                         "a" =>  Value::test_int(3),
-                        "b" =>  Value::test_int(4),
+                        "b" =>  Value::test_list(vec![
+                            Value::test_int(4),
+                            Value::test_int(4),
+                        ])
                     }),
                 ])),
             },

crates/nu-engine/src/documentation.rs

@@ -3,7 +3,7 @@ use nu_protocol::{
     ast::{Argument, Call, Expr, Expression, RecordItem},
     debugger::WithoutDebug,
     engine::{Command, EngineState, Stack, UNKNOWN_SPAN_ID},
-    record, Category, Example, IntoPipelineData, PipelineData, Signature, Span, SpanId,
+    record, Category, Example, IntoPipelineData, PipelineData, Signature, Span, SpanId, Spanned,
     SyntaxShape, Type, Value,
 };
 use std::{collections::HashMap, fmt::Write};
@@ -296,6 +296,28 @@ fn get_documentation(
         }
 
         if let Some(result) = &example.result {
+            let mut table_call = Call::new(Span::unknown());
+            if example.example.ends_with("--collapse") {
+                // collapse the result
+                table_call.add_named((
+                    Spanned {
+                        item: "collapse".to_string(),
+                        span: Span::unknown(),
+                    },
+                    None,
+                    None,
+                ))
+            } else {
+                // expand the result
+                table_call.add_named((
+                    Spanned {
+                        item: "expand".to_string(),
+                        span: Span::unknown(),
+                    },
+                    None,
+                    None,
+                ))
+            }
             let table = engine_state
                 .find_decl("table".as_bytes(), &[])
                 .and_then(|decl_id| {
@@ -304,7 +326,7 @@ fn get_documentation(
                         .run(
                             engine_state,
                             stack,
-                            &Call::new(Span::new(0, 0)),
+                            &table_call,
                             PipelineData::Value(result.clone(), None),
                         )
                         .ok()