Kind = (adjective) generous ,helpful and thinking about other people’s feelings/problems/difficulties etc.

• A kind person/action.
• She’s very kind to animals.
• It was very kind of you to visit me.

Kindly = (adverb) 1.  in a kind way.

• She spoke kindly to the old man.
• They treated me kindly.

(2) – (esp.used to show annoyance) = please

• Will you kindly put that book back?
• (OR) Kindly put it back.
• Would you kindly explain the matter a little more clearly.

(3) ;( adjective -formal) friendly, pleasantly or generous , especially to those who are younger, weaker or less important than oneself.; warm , kindhearted.

• A kindly uncle/smile.
• She was a kindly old lady.
• He is a kindly old professor.