Clean up error text

src/commands/get.rs

@@ -38,8 +38,8 @@ fn get_member(path: &Tagged<String>, obj: &Tagged<Value>) -> Result<Tagged<Value
                     Some(v) => return Ok(v.clone()),
                     None => {
                         return Err(ShellError::labeled_error(
-                            "Unknown field",
-                            "object missing field",
+                            "Unknown column",
+                            "table missing column",
                             path.span(),
                         ));
                     }

src/commands/pick.rs

@@ -35,7 +35,7 @@ fn pick(
 ) -> Result<OutputStream, ShellError> {
     if fields.len() == 0 {
         return Err(ShellError::labeled_error(
-            "Pick requires fields",
+            "Pick requires columns to pick",
             "needs parameter",
             name,
         ));