Improving variable name.

[MisterAwesome23]

An improved variable name represents what information the variable contains in a more exact sense.

[thekunalsaini]

Hi, @MisterAwesome23
As mentioned in comment what is its purpose then why to change name?

[MisterAwesome23]

Thingspeak has two API keys to start up front.
Read API key and write API key.

Now it might be confusing whether the "read" is to read from device or read from ThingsSpeak (at least was confusing to me at first)

So, writing an exact variable ensures which KEY has to be imported from ThingsSpeak removing an ambiguity.

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