docs: migrate renderer examples to buffer macro and update docs

Update all documentation and code examples to use the new
`#[renderer(buffer)]`
pattern with `r_println!` instead of manually constructing
`RenderResult`
with `writeln!`.

1 files changed, 12 insertions, 14 deletions

diff --git a/docs/pages/10-help.md b/docs/pages/10-help.md
index c17f410..1e3ea78 100644
--- a/docs/pages/10-help.md
+++ b/docs/pages/10-help.md
@@ -13,18 +13,17 @@ Write a help function directly for an Entry:
 
 ```rust
 @@@use mingling::macros::help;
+@@@use mingling::macros::buffer;
 @@@dispatcher!("greet", CMDGreet => EntryGreet);
-#[help]
-fn help_greet(entry: EntryGreet) -> RenderResult {
-    let mut r = RenderResult::new();
-    writeln!(r, "Usage: greet [name]").ok();
-    writeln!(r, "Say hello to someone.").ok();
-    r
+#[help(buffer)]
+fn help_greet(_entry: EntryGreet) {
+    r_println!("Usage: greet [name]");
+    r_println!("Say hello to someone.");
 }
 ```
  
 > [!NOTE]
-> Help functions also use `writeln!` into a `RenderResult`, because `#[help]` follows the rendering pipeline — it's a short-circuit render triggered early by the `--help` flag, not logic outside the pipeline.
+> Help functions also use `r_println!` into a `RenderResult`, because `#[help]` follows the rendering pipeline — it's a short-circuit render triggered early by the `--help` flag, not logic outside the pipeline.
 
 ## Global Help
 
@@ -32,14 +31,13 @@ You can also write help for `ErrorDispatcherNotFound` as the "root help":
 
 ```rust
 @@@use mingling::macros::help;
+@@@use mingling::macros::buffer;
 // Triggered when user passes --help directly
-#[help]
-fn help_root(entry: ErrorDispatcherNotFound) -> RenderResult {
-    let mut r = RenderResult::new();
-    writeln!(r, "Usage: my-cli <command>").ok();
-    writeln!(r, "Commands:").ok();
-    writeln!(r, "  greet    Say hello").ok();
-    r
+#[help(buffer)]
+fn help_root(entry: ErrorDispatcherNotFound) {
+    r_println!("Usage: my-cli <command>");
+    r_println!("Commands:");
+    r_println!("  greet    Say hello");
 }
 ```