Revise proc_macro_attribute text

Author: traviscross

src/procedural-macros.md

@@ -228,14 +228,15 @@ A helper attribute for a derive macro is declared by adding its identifier to th
 > }
 > ```
 
+<!-- template:attributes -->
 r[macro.proc.attribute]
 ## The `proc_macro_attribute` attribute
 
 r[macro.proc.attribute.intro]
 The *`proc_macro_attribute` [attribute][attributes]* defines an *attribute macro* which can be used as an [outer attribute][attributes].
 
 > [!EXAMPLE]
-> The following attribute macro takes the input stream and returns it as is, effectively being the no-op of attributes.
+> This attribute macro takes the input stream and emits it as-is, effectively being a no-op attribute.
 >
 > <!-- ignore: test doesn't support proc-macro -->
 > ```rust,ignore
@@ -250,7 +251,7 @@ The *`proc_macro_attribute` [attribute][attributes]* defines an *attribute macro
 > ```
 
 > [!EXAMPLE]
-> This following example shows the stringified [`TokenStream`s] that the attribute macros see. The output will show in the output of the compiler. The output is shown in the comments after the function prefixed with "out:".
+> This shows, in the output of the compiler, the stringified [`TokenStream`s] that attribute macros see.
 >
 > <!-- ignore: test doesn't support proc-macro -->
 > ```rust,ignore
@@ -273,36 +274,36 @@ The *`proc_macro_attribute` [attribute][attributes]* defines an *attribute macro
 >
 > use my_macro::show_streams;
 >
-> // Example: Basic function
+> // Example: Basic function.
 > #[show_streams]
 > fn invoke1() {}
 > // out: attr: ""
 > // out: item: "fn invoke1() {}"
 >
-> // Example: Attribute with input
+> // Example: Attribute with input.
 > #[show_streams(bar)]
 > fn invoke2() {}
 > // out: attr: "bar"
 > // out: item: "fn invoke2() {}"
 >
-> // Example: Multiple tokens in the input
+> // Example: Multiple tokens in the input.
 > #[show_streams(multiple => tokens)]
 > fn invoke3() {}
 > // out: attr: "multiple => tokens"
 > // out: item: "fn invoke3() {}"
 >
-> // Example:
+> // Example: Delimiters in the input.
 > #[show_streams { delimiters }]
 > fn invoke4() {}
 > // out: attr: "delimiters"
 > // out: item: "fn invoke4() {}"
 > ```
 
 r[macro.proc.attribute.syntax]
-The `proc_macro_attribute` attribute uses the [MetaWord] syntax and thus does not take any inputs.
+The `proc_macro_attribute` attribute uses the [MetaWord] syntax.
 
 r[macro.proc.attribute.allowed-positions]
-The `proc_macro_attribute` attribute may only be applied to a function with the signature of `pub fn(TokenStream, TokenStream) -> TokenStream` where [`TokenStream`] comes from the [`proc_macro` crate]. It must have the ["Rust" ABI][items.fn.extern]. No other function qualifiers are allowed.
+The `proc_macro_attribute` attribute may only be applied to a `pub` function of type `fn(TokenStream, TokenStream) -> TokenStream` where [`TokenStream`] comes from the [`proc_macro` crate]. It must have the ["Rust" ABI][items.fn.extern]. No other function qualifiers are allowed. It must be located in the root of the crate.
 
 r[macro.proc.attribute.duplicates]
 The `proc_macro_attribute` attribute may only be specified once on a function.