Update README.md

Groups: fixed one broken link, added polysci, alphabetised.

README.md

@@ -69,22 +69,23 @@ There are also groups over on Mastodon that you can use to connect to fellow aca
 - [@academicsunite@a.gup.pe](https://a.gup.pe/u/academicsunite) (academic working conditions)
 - [@ancientneareast@a.gup.pe](https://a.gup.pe/u/ancientneareast)
 - [@anthropology@a.gup.pe](https://social.tchncs.de/web/@anthropology@a.gup.pe)
-- [@archaeodons@a.gup.pe](https://social.tchncs.de/web/@archaeodons@a.gup.pe)
 - [@antiquidons@a.gup.pe](https://a.gup.pe/u/antiquidons)
+- [@archaeodons@a.gup.pe](https://social.tchncs.de/web/@archaeodons@a.gup.pe)
+- [@biophysics@a.gup.pe](@biophysics@a.gup.pe)
 - [@cognition@a.gup.pe](https://a.gup.pe/u/cognition) (cognitive psychology)
 - [@cogsci@a.gup.pe](https://a.gup.pe/u/cogsci)
 - [@ecologies@a.gup.pe](https://a.gup.pe/u/ecologies)
 - [@edutooters@a.gup.pe](https://a.gup.pe/u/edutooters)
 - [@geodons@a.gup.pe](https://a.gup.pe/u/geodons)
 - [@histodons@a.gup.pe](https://a.gup.pe/u/histodons)
+- [@julialang@a.gup.pe](https://a.gup.pe/u/julialang) (The Julia programming language)
+- [@mechanobiology@a.gup.pe](@mechanobiology@a.gup.pe)
 - [@paleodons@a.gup.pe](https://a.gup.pe/u/paleodons)
 - [@philosophy@a.gup.pe](https://a.gup.pe/u/philosophy)
+- [@politicalscience@a.gup.pe](@politicalscience@a.gup.pe)
+- [@rstats@a.gup.pe](https://a.gup.pe/u/rstats) (The R language for statistical computing)
 - [@seresearchers@a.gup.pe](https://a.gup.pe/u/seresearchers) (Software Engineering)
 - [@sociology@a.gup.pe](https://a.gup.pe/u/sociology)
-- [@rstats@a.gup.pe](https://a.gup.pe/u/rstats) (The R language for statistical computing)
-- [@mechanobiology@a.gup.pe](@mechanobiology@a.gup.pe)
-- [@biophysics@a.gup.pe](@mechanobiology@a.gup.pe)
-- [@julialang@a.gup.pe](https://a.gup.pe/u/julialang) (The Julia programming language)
 
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