Fix broken links

Author: hynek

AUTHORS.rst

@@ -8,4 +8,4 @@ The development is kindly supported by `Variomedia AG <https://www.variomedia.de
 A full list of contributors can be found in `GitHub's overview <https://github.com/python-attrs/attrs/graphs/contributors>`_.
 
 It’s the spiritual successor of `characteristic <https://characteristic.readthedocs.io/>`_ and aspires to fix some of it clunkiness and unfortunate decisions.
-Both were inspired by Twisted’s `FancyEqMixin <https://twistedmatrix.com/documents/current/api/twisted.python.util.FancyEqMixin.html>`_ but both are implemented using class decorators because `subclassing is bad for you <https://www.youtube.com/watch?v=3MNVP9-hglc>`_, m’kay?
+Both were inspired by Twisted’s `FancyEqMixin <https://docs.twisted.org/en/stable/api/twisted.python.util.FancyEqMixin.html>`_ but both are implemented using class decorators because `subclassing is bad for you <https://www.youtube.com/watch?v=3MNVP9-hglc>`_, m’kay?

README.rst

@@ -23,7 +23,7 @@
 .. teaser-begin
 
 ``attrs`` is the Python package that will bring back the **joy** of **writing classes** by relieving you from the drudgery of implementing object protocols (aka `dunder methods <https://www.attrs.org/en/latest/glossary.html#term-dunder-methods>`_).
-`Trusted by NASA <https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-github-profile/customizing-your-profile/personalizing-your-profile#list-of-qualifying-repositories-for-mars-2020-helicopter-contributor-badge>`_ for Mars missions since 2020!
+`Trusted by NASA <https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-github-profile/customizing-your-profile/personalizing-your-profile#list-of-qualifying-repositories-for-mars-2020-helicopter-contributor-achievement>`_ for Mars missions since 2020!
 
 Its main goal is to help you to write **concise** and **correct** software without slowing down your code.