Add release notes

.release-notes/fix_cli.md

@@ -0,0 +1,24 @@
+## Fix `cli` package from mangling options with equal signs
+
+The current command parser in the `cli` package cuts option arguments of `String` type at the first equal sign. This release fixes the problem for long options (`--option=foo=bar`) and for short options such as `-O=foo=bar`. Short options such as `-Ofoo=bar` will continue to raise an "ambiguous args" error.
+
+The code below shows the bug, with the option argument being cut short at the first equal sign. The code below prints "foo" instead of the complete value, "foo=bar". The same is true when uses the short version of the option, like `-t=foo=bar`.
+
+```pony
+use "cli"
+
+actor Main
+  new create(env: Env) =>
+    try
+      let cs =
+        CommandSpec.leaf("simple", "", [
+          OptionSpec.string("test" where short' = 't')
+        ])?
+      
+      let args: Array[String] = [
+        "ignored"; "--test=foo=bar"
+      ]
+      let cmdErr = CommandParser(cs).parse(args) as Command
+      env.out.print(cmdErr.option("test").string())
+    end
+```