Bump postcss from 7.0.26 to 7.0.39 in /docs-site

Bumps [postcss](https://github.com/postcss/postcss) from 7.0.26 to 7.0.39.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/7.0.39/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/7.0.26...7.0.39)

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

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/docs-site/yarn.lock b/docs-site/yarn.lock
index 89624e9..e106239 100644
--- a/docs-site/yarn.lock
+++ b/docs-site/yarn.lock
@@ -5823,6 +5823,11 @@
   resolved "https://registry.yarnpkg.com/performance-now/-/performance-now-2.1.0.tgz#6309f4e0e5fa913ec1c69307ae364b4b377c9e7b"
   integrity sha1-Ywn04OX6kT7BxpMHrjZLSzd8nns=
 
+picocolors@^0.2.1:
+  version "0.2.1"
+  resolved "https://registry.yarnpkg.com/picocolors/-/picocolors-0.2.1.tgz#570670f793646851d1ba135996962abad587859f"
+  integrity sha512-cMlDqaLEqfSaW8Z7N5Jw+lyIW869EzT73/F5lhtY9cLGoVxSXznfgfXMO0Z5K0o0Q2TkTXq+0KFsdnSe3jDViA==
+
 picomatch@^2.0.4, picomatch@^2.0.5, picomatch@^2.0.7:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/picomatch/-/picomatch-2.1.1.tgz#ecdfbea7704adb5fe6fb47f9866c4c0e15e905c5"
@@ -6188,13 +6193,12 @@
   integrity sha512-LmeoohTpp/K4UiyQCwuGWlONxXamGzCMtFxLq4W1nZVGIQLYvMCJx3yAF9qyyuFpflABI9yVdtJAqbihOsCsJQ==
 
 postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.23, postcss@^7.0.5:
-  version "7.0.26"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-7.0.26.tgz#5ed615cfcab35ba9bbb82414a4fa88ea10429587"
-  integrity sha512-IY4oRjpXWYshuTDFxMVkJDtWIk2LhsTlu8bZnbEJA4+bYT16Lvpo8Qv6EvDumhYRgzjZl489pmsY3qVgJQ08nA==
+  version "7.0.39"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-7.0.39.tgz#9624375d965630e2e1f2c02a935c82a59cb48309"
+  integrity sha512-yioayjNbHn6z1/Bywyb2Y4s3yvDAeXGOyxqD+LnVOinq6Mdmd++SW2wUNVzavyyHxd6+DxzWGIuosg6P1Rj8uA==
   dependencies:
-    chalk "^2.4.2"
+    picocolors "^0.2.1"
     source-map "^0.6.1"
-    supports-color "^6.1.0"
 
 prelude-ls@~1.1.2:
   version "1.1.2"
@@ -7679,7 +7683,7 @@
   dependencies:
     has-flag "^3.0.0"
 
-supports-color@^6.0.0, supports-color@^6.1.0:
+supports-color@^6.0.0:
   version "6.1.0"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-6.1.0.tgz#0764abc69c63d5ac842dd4867e8d025e880df8f3"
   integrity sha512-qe1jfm1Mg7Nq/NSh6XE24gPXROEVsWHxC1LIx//XNlD9iw7YZQGjZNjYN7xGaEG6iKdA8EtNFW6R0gjnVXp+wQ==