fix broken links, update ZuriHac link

Author: kukimik

affiliates/stackage.markdown

@@ -1,5 +1,5 @@
 ---
 title: Stackage Curators
-externalUrl: https://github.com/commercialhaskell/stackage/blob/master/CURATORS.m
+externalUrl: https://github.com/commercialhaskell/stackage/blob/master/CURATORS.md
 status: affiliated
 ---

affiliates/zurihac.markdown

@@ -1,5 +1,5 @@
 ---
 title: Zurihac
-externalUrl: https://zfoh.ch/zurihac2021/
+externalUrl: https://zurihac.com/
 status: affiliated
 ---

donations/sponsors/mlabs.markdown

@@ -1,7 +1,7 @@
 ---
 title: MLabs
 externalUrl: https://mlabs.city/
-careersUrl: https://mlabs.city/careers.html
+careersUrl: https://apply.workable.com/mlabs/
 logo: /assets/images/sponsors/mlabs/logo-black-pink.png
 level: Functor
 ---

guidelines-for-respectful-communication/index.html

@@ -56,7 +56,7 @@ <h2>Acknowledgements</h2>
       <li><a href="https://github.com/todogroup/opencodeofconduct/blob/gh-pages/index.md" target="_blank">Open code of conduct</a></li>
       <li><a href="https://github.com/python/pycon-code-of-conduct/blob/master/code_of_conduct.md" target="_blank">Pycon code of conduct</a></li>
       <li><a href="https://www.rust-lang.org/policies/code-of-conduct" target="_blank">Rust code of conduct</a></li>
-      <li><a href="https://typelevel.org/conduct.html" target="_blank">TypeLevel code of conduct</a></li>
+      <li><a href="https://typelevel.org/code-of-conduct" target="_blank">TypeLevel code of conduct</a></li>
       <li><a href="https://www.contributor-covenant.org/" target="_blank">Contributor covenant</a></li>
     </ul>