feat(into): add into-bool command (#499)

* feat(into): add example of into-bool

* feat(into): add convert from int and float

* feat(into): add converting string to bool

* feat(into): add converting value in table

* fix(into): update error

* fix(into): update span for example

* chore(into): update signature description

* float comparison using epsilon

* Update bool.rs

Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>

crates/nu-command/src/default_context.rs

@@ -219,6 +219,7 @@ pub fn create_default_context() -> EngineState {
         // Conversions
         bind_command! {
             Into,
+            IntoBool,
             IntoBinary,
             IntoDatetime,
             IntoDecimal,