removed non-working twitter link in docs/source/contributing/developer_guide.md and changed twitter link to X in readme.rst

Author: Demon-Sheriff

README.rst

@@ -222,7 +222,7 @@ You can also follow us on these social media platforms for updates and other ann
 
 - `LinkedIn @pymc <https://www.linkedin.com/company/pymc/>`__
 - `YouTube @PyMCDevelopers <https://www.youtube.com/c/PyMCDevelopers>`__
-- `Twitter @pymc_devs <https://twitter.com/pymc_devs>`__
+- `X @pymc_devs <https://x.com/pymc_devs>`__
 - `Mastodon @[email protected] <https://bayes.club/@pymc>`__
 
 To report an issue with PyMC please use the `issue tracker <https://github.com/pymc-devs/pymc/issues>`__.

docs/source/contributing/developer_guide.md

@@ -173,7 +173,7 @@ self.logp_nojac_unscaledt = distribution.logp_nojac(data)
 
 ### Model context and Random Variable
 
-I like to think that the ``with pm.Model() ...`` is a key syntax feature and *the* signature of PyMC model language, and in general a great out-of-the-box thinking/usage of the context manager in Python (with [some critics](https://twitter.com/_szhang/status/890793373740617729), of course).
+I like to think that the ``with pm.Model() ...`` is a key syntax feature and *the* signature of PyMC model language, and in general a great out-of-the-box thinking/usage of the context manager in Python (with some critics, of course).
 
 Essentially [what a context manager does](https://www.python.org/dev/peps/pep-0343/) is: