Update readme for new API

README.md

@@ -26,23 +26,20 @@ This approach works with any stable or nightly Rust compiler 1.30+.
 
 ## Pasting identifiers
 
-There are two entry points, `paste::expr!` for macros in expression position and
-`paste::item!` for macros in item position.
-
-Within either one, identifiers inside `[<`...`>]` are pasted together to form a
-single identifier.
+Within the `paste!` macro, identifiers inside `[<`...`>]` are pasted together to
+form a single identifier.
 
 ```rust
-// Macro in item position: at module scope or inside of an impl block.
-paste::item! {
+use paste::paste;
+
+paste! {
     // Defines a const called `QRST`.
     const [<Q R S T>]: &str = "success!";
 }
 
 fn main() {
-    // Macro in expression position: inside a function body.
     assert_eq!(
-        paste::expr! { [<Q R S T>].len() },
+        paste! { [<Q R S T>].len() },
         8,
     );
 }
@@ -57,12 +54,14 @@ of a more convenient user-facing macro of your own. Here the `routes!(A, B)`
 macro expands to a vector containing `ROUTE_A` and `ROUTE_B`.
 
 ```rust
+use paste::paste;
+
 const ROUTE_A: &str = "/a";
 const ROUTE_B: &str = "/b";
 
 macro_rules! routes {
     ($($route:ident),*) => {{
-        paste::expr! {
+        paste! {
             vec![$( [<ROUTE_ $route>] ),*]
         }
     }}
@@ -78,6 +77,8 @@ The next example shows a macro that generates accessor methods for some struct
 fields.
 
 ```rust
+use paste::paste;
+
 macro_rules! make_a_struct_and_getters {
     ($name:ident { $($field:ident),* }) => {
         // Define a struct. This expands to:
@@ -100,7 +101,7 @@ macro_rules! make_a_struct_and_getters {
         //         pub fn get_b(&self) -> &str { &self.b }
         //         pub fn get_c(&self) -> &str { &self.c }
         //     }
-        paste::item! {
+        paste! {
             impl $name {
                 $(
                     pub fn [<get_ $field>](&self) -> &str {