Fix an into bits example (#12668)

# Description
One example for `into bits` says it uses binary value when it actually
uses a filesize. This lead to issue #11412, but I never got around to
fixing the example until this PR.

crates/nu-cmd-extra/src/extra/bits/into.rs

@@ -64,7 +64,7 @@ impl Command for BitsInto {
  vec![
  Example {
  description: "convert a binary value into a string, padded to 8 places with 0s",
- example: "01b | into bits",
+ example: "0x[1] | into bits",
  result: Some(Value::string("00000001",
  Span::test_data(),
  )),