Document version of :start/:stop events (tracers) (#9871)

Author: fertapric

lib/elixir/lib/code.ex

@@ -43,14 +43,14 @@ defmodule Code do
   You can configure your list of tracers via `put_compiler_option/2`. The
   following events are available to tracers:
 
-    * `:start` - invoked whenever the compiler starts to trace a new lexical
-      context, such as a new file. Keep in mind the compiler runs in parallel,
-      so multiple files may invoke `:start` and run at the same time. The value
-      of the `lexical_tracker` of the macro environment, albeit opaque, can be
-      used to uniquely identify the environment
-
-    * `:stop` - invoked whenever the compiler stops tracing a new lexical
-      context, such as a new file
+    * `:start` - (since v1.11.0) invoked whenever the compiler starts to trace
+      a new lexical context, such as a new file. Keep in mind the compiler runs
+      in parallel, so multiple files may invoke `:start` and run at the same
+      time. The value of the `lexical_tracker` of the macro environment, albeit
+      opaque, can be used to uniquely identify the environment.
+
+    * `:stop` - (since v1.11.0) invoked whenever the compiler stops tracing a
+      new lexical context, such as a new file.
 
     * `{:import, meta, module, opts}` - traced whenever `module` is imported.
       `meta` is the import AST metadata and `opts` are the import options.