Category option for signature (#343)

* category option for signature

* category option for signature

* column description for $scope

crates/nu-command/src/system/benchmark.rs

@@ -3,7 +3,7 @@ use std::time::Instant;
 use nu_engine::eval_block;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
-use nu_protocol::{IntoPipelineData, PipelineData, Signature, SyntaxShape, Value};
+use nu_protocol::{Category, IntoPipelineData, PipelineData, Signature, SyntaxShape, Value};
 
 #[derive(Clone)]
 pub struct Benchmark;
@@ -18,11 +18,13 @@ impl Command for Benchmark {
     }
 
     fn signature(&self) -> nu_protocol::Signature {
-        Signature::build("benchmark").required(
-            "block",
-            SyntaxShape::Block(Some(vec![])),
-            "the block to run",
-        )
+        Signature::build("benchmark")
+            .required(
+                "block",
+                SyntaxShape::Block(Some(vec![])),
+                "the block to run",
+            )
+            .category(Category::System)
     }
 
     fn run(

crates/nu-command/src/system/ps.rs

@@ -1,7 +1,7 @@
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Value,
+    Category, Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Value,
 };
 use sysinfo::{ProcessExt, System, SystemExt};
 
@@ -22,6 +22,7 @@ impl Command for Ps {
                 Some('l'),
             )
             .filter()
+            .category(Category::System)
     }
 
     fn usage(&self) -> &str {

crates/nu-command/src/system/run_external.rs

@@ -8,7 +8,7 @@ use std::sync::mpsc;
 
 use nu_protocol::engine::{EngineState, Stack};
 use nu_protocol::{ast::Call, engine::Command, ShellError, Signature, SyntaxShape, Value};
-use nu_protocol::{Config, IntoInterruptiblePipelineData, PipelineData, Span, Spanned};
+use nu_protocol::{Category, Config, IntoInterruptiblePipelineData, PipelineData, Span, Spanned};
 
 use nu_engine::CallExt;
 
@@ -26,10 +26,15 @@ impl Command for External {
         "Runs external command"
     }
 
+    fn is_private(&self) -> bool {
+        true
+    }
+
     fn signature(&self) -> nu_protocol::Signature {
         Signature::build("run_external")
             .switch("last_expression", "last_expression", None)
             .rest("rest", SyntaxShape::Any, "external command to run")
+            .category(Category::System)
     }
 
     fn run(

crates/nu-command/src/system/sys.rs

@@ -1,7 +1,7 @@
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Value,
 };
 use sysinfo::{ComponentExt, DiskExt, NetworkExt, ProcessorExt, System, SystemExt, UserExt};
 
@@ -17,6 +17,7 @@ impl Command for Sys {
         Signature::build("sys")
             .desc("View information about the current system.")
             .filter()
+            .category(Category::System)
     }
 
     fn usage(&self) -> &str {