[TYPO3-english] RTE CKEditor

[Guy Newell]

Hi Everyone,

I am using TYPO3 8.7.1 and want to override some of the settings in the RTE CKEditor. 
I have read the excellent article at typo3worx.eu and understand about the yaml files. 
I do not want to edit the yaml files in the TYPO3 source as these will be overwritten on the next software release, so how do I tell TYPO3 about my own overrides? Do I need to create an extension for example?

Many Thanks for your help ... Guy