Experiment: Allow both $true/true and $false/false (#4696)

* Change true/false to keywords

* oops, clippy

* Both kinds of bools

* Add in some boolean variables

* disable py virtualenv test for now

crates/nu-command/src/conversions/into/binary.rs

@@ -61,7 +61,7 @@ impl Command for SubCommand {
             },
             Example {
                 description: "convert a boolean to a nushell binary primitive",
-                example: "$true | into binary",
+                example: "true | into binary",
                 result: Some(Value::Binary {
                     val: i64::from(1).to_le_bytes().to_vec(),
                     span: Span::test_data(),