Updated description

python-typing-extensions.spec

@@ -17,21 +17,30 @@ BuildRequires: python3-pytest
 
 
 %global _description %{expand:
-Typing Extensions - Backported and Experimental Type Hints for Python
-
-The typing module was added to the standard library in Python 3.5 on a
-provisional basis and will no longer be provisional in Python 3.7.
-However, this means users of Python 3.5 - 3.6 who are unable to upgrade will not
-be able to take advantage of new types added to the typing module, such as
-typing.Text or typing.Coroutine.
-
-The typing_extensions module contains both backports of these changes as well as
-experimental types that will eventually be added to the typing module, such as
-Protocol.
-
-Users of other Python versions should continue to install and use the typing
-module from PyPi instead of using this one unless specifically writing code that
-must be compatible with multiple Python versions or requires experimental types.}
+The `typing_extensions` module serves two related purposes:
+
+- Enable use of new type system features on older Python versions. For example,
+  `typing.TypeGuard` is new in Python 3.10, but `typing_extensions` allows
+  users on Python 3.6 through 3.9 to use it too.
+- Enable experimentation with new type system PEPs before they are accepted and
+  added to the `typing` module.
+
+New features may be added to `typing_extensions` as soon as they are specified
+in a PEP that has been added to the [python/peps](https://github.com/python/peps)
+repository. If the PEP is accepted, the feature will then be added to `typing`
+for the next CPython release. No typing PEP has been rejected so far, so we
+haven't yet figured out how to deal with that possibility.
+
+Starting with version 4.0.0, `typing_extensions` uses
+[Semantic Versioning](https://semver.org/). The
+major version is incremented for all backwards-incompatible changes.
+Therefore, it's safe to depend
+on `typing_extensions` like this: `typing_extensions >=x.y, <(x+1)`,
+where `x.y` is the first version that includes all features you need.
+
+`typing_extensions` supports Python versions 3.7 and higher. In the future,
+support for older Python versions will be dropped some time after that version
+reaches end of life.}
 
 %description %_description