refactor: rename DTree to DValue

site/doc/pages/cli_input.txt

@@ -2,17 +2,17 @@
 cli_input
 
 :sig
-DTree cli_input(Request& context)
+DValue cli_input(Request& context)
 
 :see
 >1_CLI
 >json_decode
->DTree
+>DValue
 
 :content
 Returns a structured parameter tree for a `CLI(Request& context)` invocation.
 
-`cli_input()` merges simple command inputs into one `DTree`:
+`cli_input()` merges simple command inputs into one `DValue`:
 
 1. query parameters from `context.get`
 2. form parameters from `context.post`
@@ -25,7 +25,7 @@ If the JSON body is a scalar or array instead of an object, the decoded value is
 ```cpp
 CLI(Request& context)
 {
-    DTree input = cli_input(context);
+    DValue input = cli_input(context);
     String action = first(input["action"].to_string(), "help");
 
     if(action == "echo")