HI Community
There is a documentation covering configuring of RTE :- https://docs.adobe.com/docs/en/aem/6-1/administer/operations/page-authoring/rich-text-editor.html
Apart from the one mentioned above, some good article be considered as reference for RTE are:-
Link:- http://experience-aem.blogspot.in/2015/01/aem-6-sp1-touchui-richtext-editor-color-picker-plugin.html
Link:- https://helpx.adobe.com/experience-manager/using/creating-aem-multifield-components.html
Link:- https://helpx.adobe.com/experience-manager/kb/creating-cq-widget-supports-image.html
I hope this would help community.
Thanks and Regards
Kautuk Sahni