Mark all uses of the attributes template

It's helpful to know when a section follows a particular template and
to be able to quickly search for all uses of that template.  Let's
label all uses of the attributes template.

Author: traviscross

docs/attribute-template.md

@@ -6,6 +6,7 @@ When an attribute (or a new attribute position in the grammar) is added, be sure
 
 ----
 
+<!-- template:attributes -->
 r[PARENT.example]
 ## The `example` attribute
 

src/attributes/codegen.md

@@ -82,6 +82,7 @@ The [`track_caller`](#the-track_caller-attribute) attribute cannot be applied to
 r[attributes.codegen.naked.testing]
 The [testing attributes](testing.md) cannot be applied to a naked function.
 
+<!-- template:attributes -->
 r[attributes.codegen.no_builtins]
 ## The `no_builtins` attribute
 

src/attributes/derive.md

@@ -1,3 +1,4 @@
+<!-- template:attributes -->
 r[attributes.derive]
 # Derive
 
@@ -63,6 +64,7 @@ The built-in derives include the [`automatically_derived` attribute][attributes.
 r[attributes.derive.behavior]
 During macro expansion, for each element in the list of derives, the corresponding derive macro expands to zero or more [items].
 
+<!-- template:attributes -->
 r[attributes.derive.automatically_derived]
 ## The `automatically_derived` attribute
 

src/attributes/limits.md

@@ -40,6 +40,7 @@ a!{}
 (|_: &u8| {})(&&&1);
 ```
 
+<!-- template:attributes -->
 r[attributes.limits.type_length_limit]
 ## The `type_length_limit` attribute
 

src/attributes/testing.md

@@ -6,6 +6,7 @@ tests. Compiling a crate in "test" mode enables building the test functions
 along with a test harness for executing the tests. Enabling the test mode also
 enables the [`test` conditional compilation option].
 
+<!-- template:attributes -->
 r[attributes.testing.test]
 ## The `test` attribute
 
@@ -71,6 +72,7 @@ In particular:
 > }
 > ```
 
+<!-- template:attributes -->
 r[attributes.testing.ignore]
 ## The `ignore` attribute
 
@@ -119,6 +121,7 @@ Only the first instance of `ignore` on a function is honored.
 r[attributes.testing.ignore.behavior]
 Ignored tests are still compiled when in test mode, but they are not executed.
 
+<!-- template:attributes -->
 r[attributes.testing.should_panic]
 ## The `should_panic` attribute
 

src/conditional-compilation.md

@@ -315,6 +315,7 @@ Example values:
 
 ## Forms of conditional compilation
 
+<!-- template:attributes -->
 r[cfg.attr]
 ### The `cfg` attribute
 
@@ -388,6 +389,7 @@ When a crate-level `cfg` has a false predicate, the crate itself still exists. A
 > pub fn example() {}
 > ```
 
+<!-- template:attributes -->
 r[cfg.cfg_attr]
 ### The `cfg_attr` attribute
 

src/items/extern-crates.md

@@ -73,6 +73,7 @@ r[items.extern-crate.underscore.macro_use]
 The [`macro_use` attribute] works as usual and imports the macro names
 into the [`macro_use` prelude].
 
+<!-- template:attributes -->
 r[items.extern-crate.no_link]
 ## The `no_link` attribute
 

src/items/external-blocks.md

@@ -391,6 +391,7 @@ r[items.extern.attributes.link.import_name_type.platform-specific]
 The `import_name_type` key is only supported on x86 Windows. Using it when
 targeting other platforms will result in a compiler error.
 
+<!-- template:attributes -->
 r[items.extern.attributes.link_name]
 ### The `link_name` attribute
 

src/procedural-macros.md

@@ -130,6 +130,7 @@ position, which includes [statements], [expressions], [patterns], [type
 expressions], [item] positions, including items in [`extern` blocks], inherent
 and trait [implementations], and [trait definitions].
 
+<!-- template:attributes -->
 r[macro.proc.derive]
 ## The `proc_macro_derive` attribute
 

src/runtime.md

@@ -3,6 +3,7 @@ r[runtime]
 
 This section documents features that define some aspects of the Rust runtime.
 
+<!-- template:attributes -->
 r[runtime.global_allocator]
 ## The `global_allocator` attribute
 
@@ -44,6 +45,7 @@ The `global_allocator` attribute may only be used once in the crate graph.
 r[runtime.global_allocator.stdlib]
 The `global_allocator` attribute is exported from the [standard library prelude][core::prelude::v1].
 
+<!-- template:attributes -->
 r[runtime.windows_subsystem]
 ## The `windows_subsystem` attribute