build(deps): Bump postcss from 8.4.24 to 8.4.31 in /docs

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.24 to 8.4.31.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.24...8.4.31)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

docs/yarn.lock

@@ -1436,19 +1436,10 @@ postcss-value-parser@^4.2.0:
   resolved "https://registry.yarnpkg.com/postcss-value-parser/-/postcss-value-parser-4.2.0.tgz#723c09920836ba6d3e5af019f92bc0971c02e514"
   integrity sha512-1NNCs6uurfkVbeXG4S8JFT9t19m45ICnif8zWLd5oPSZ50QnwMfK+H3jv408d4jw/7Bttv5axS5IiHoLaVNHeQ==
 
-postcss@^8.1.10:
-  version "8.4.24"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.24.tgz#f714dba9b2284be3cc07dbd2fc57ee4dc972d2df"
-  integrity sha512-M0RzbcI0sO/XJNucsGjvWU9ERWxb/ytp1w6dKtxTKgixdtQDq4rmx/g8W1hnaheq9jgwL/oyEdH5Bc4WwJKMqg==
-  dependencies:
-    nanoid "^3.3.6"
-    picocolors "^1.0.0"
-    source-map-js "^1.0.2"
-
-postcss@^8.4.27, postcss@^8.4.28:
-  version "8.4.28"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.28.tgz#c6cc681ed00109072816e1557f889ef51cf950a5"
-  integrity sha512-Z7V5j0cq8oEKyejIKfpD8b4eBy9cwW2JWPk0+fB1HOAMsfHbnAXLLS+PfVWlzMSLQaWttKDt607I0XHmpE67Vw==
+postcss@^8.1.10, postcss@^8.4.27, postcss@^8.4.28:
+  version "8.4.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.31.tgz#92b451050a9f914da6755af352bdc0192508656d"
+  integrity sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==
   dependencies:
     nanoid "^3.3.6"
     picocolors "^1.0.0"