Fix typo in Readme (SeleniumHQ#1606)

[skip ci]

Author: rklec

README.md

@@ -50,7 +50,7 @@ Talk to us at https://www.selenium.dev/support/
 * [Building the images](#building-the-images)
 * [Waiting for the Grid to be ready](#waiting-for-the-grid-to-be-ready)
 * [Debugging](#debugging)
-* [Install cerificates for Chromium based browsers](#install-cerificates-for-Chromium-based-browsers)
+* [Install certificates for Chromium based browsers](#install-certificates-for-Chromium-based-browsers)
 * [Troubleshooting](#troubleshooting)
 
 
@@ -859,7 +859,7 @@ Like this, the script will poll until the Grid is ready, and then your tests wil
 
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-## Install cerificates for Chromium based browsers
+## Install certificates for Chromium based browsers
 
 If you need to install custom certificates, CA, intermediate CA, client certificates (for exmample enterprise internal CA)
 you can use the different utils come from libnss3-tools.