chore(deps): bump validator from 13.7.0 to 13.15.20 in /client/docs

Bumps [validator](https://github.com/validatorjs/validator.js) from 13.7.0 to 13.15.20.
- [Release notes](https://github.com/validatorjs/validator.js/releases)
- [Changelog](https://github.com/validatorjs/validator.js/blob/master/CHANGELOG.md)
- [Commits](validatorjs/validator.js@13.7.0...13.15.20)

---
updated-dependencies:
- dependency-name: validator
  dependency-version: 13.15.20
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

client/docs/yarn.lock

@@ -1844,9 +1844,9 @@ util@^0.11.0:
     inherits "2.0.3"
 
 validator@^13.7.0:
-  version "13.7.0"
-  resolved "https://registry.yarnpkg.com/validator/-/validator-13.7.0.tgz#4f9658ba13ba8f3d82ee881d3516489ea85c0857"
-  integrity sha512-nYXQLCBkpJ8X6ltALua9dRrZDHVYxjJ1wgskNt1lH9fzGjs3tgojGSCBjmEPwkWS1y29+DrizMTW19Pr9uB2nw==
+  version "13.15.20"
+  resolved "https://registry.yarnpkg.com/validator/-/validator-13.15.20.tgz#054e9238109538a1bf46ae3e1290845a64fa2186"
+  integrity sha512-KxPOq3V2LmfQPP4eqf3Mq/zrT0Dqp2Vmx2Bn285LwVahLc+CsxOM0crBHczm8ijlcjZ0Q5Xd6LW3z3odTPnlrw==
 
 vm-browserify@^1.0.1:
   version "1.1.2"