Update most common delimeters in Markdown ANSI rendering (#15564)

Author: AlexGx

lib/elixir/lib/io/ansi/docs.ex

@@ -673,7 +673,7 @@ defmodule IO.ANSI.Docs do
 
   # Characters that can mark the beginning or the end of a word.
   # Only support the most common ones at this moment.
-  @delimiters [?\s, ?', ?", ?!, ?@, ?#, ?$, ?%, ?^, ?&] ++
+  @delimiters [?\s, ?', ?", ?!, ??, ?,, ?:, ?;, ?/, ?@, ?#, ?$, ?%, ?^, ?&] ++
                 [?-, ?+, ?(, ?), ?[, ?], ?{, ?}, ?<, ?>, ?.]
 
   ### Inline start

lib/elixir/test/elixir/io/ansi/docs_test.exs

@@ -317,6 +317,23 @@ defmodule IO.ANSI.DocsTest do
       assert result == "\e[36mhello world\e[0m\n\e[0m"
     end
 
+    test "star/underscore works before punctuation" do
+      result = format_markdown("**hello world**,")
+      assert result == "\e[1mhello world\e[0m,\n\e[0m"
+
+      result = format_markdown("*hello world*;")
+      assert result == "\e[4mhello world\e[0m;\n\e[0m"
+
+      result = format_markdown("__hello world__:")
+      assert result == "\e[1mhello world\e[0m:\n\e[0m"
+
+      result = format_markdown("_hello world_?")
+      assert result == "\e[4mhello world\e[0m?\n\e[0m"
+
+      result = format_markdown("*hello world*/")
+      assert result == "\e[4mhello world\e[0m/\n\e[0m"
+    end
+
     test "star/underscore/backtick works across words with ansi disabled" do
       result = format_markdown("*hello world*", enabled: false)
       assert result == "*hello world*"