moving gdoc comments from Annie and Kristen from gdoc to here

Under "Layers" in README.md: "Is there a maximum number of overlays? Could you add documentation for how to import overlays?"
Under "Annotations" in README.md: there is a sentence "Colors cannot be changed." from Kristen: "Is this true?"
Under "Feature Annotation" in README.md: At the start where it says "Here, we annotate the features or overlays", should "overlays" be "layers"?
Under "Feature Annotation" in README.md: it says " The ability to draw ROIs is available to facilitate annotation". Kristen says "I don't know what is meant by this and found it confusing why ROI is being used under feature annotation, so maybe this needs clarity."

chaichontat / samui