Move history into their own module (#11308)

# Description

Since there are plans to add more history commands, it seems sensible to
put them into their own module and category

https://github.com/nushell/nushell/pull/10440#issuecomment-1731408785

# User-Facing Changes

The history commands are in the category "History" rather than "Misc"

crates/nu-protocol/src/signature.rs

@@ -58,6 +58,7 @@ pub enum Category {
     Formats,
     Generators,
     Hash,
+    History,
     Math,
     Misc,
     Network,
@@ -91,6 +92,7 @@ impl std::fmt::Display for Category {
             Category::Formats => "formats",
             Category::Generators => "generators",
             Category::Hash => "hash",
+            Category::History => "history",
             Category::Math => "math",
             Category::Misc => "misc",
             Category::Network => "network",