Fix: solves the duplicate variable name error in styles-to-variables plugin

[JonatasT]

Hello! I believe the root cause of the issue #142 stems from having multiple styles associated with the same "token" name. To avoid a repeat of this incident, we can rectify the tokenData by appending a numerical suffix to the token style names. That being said, I have devised an alternate solution that may be of interest to you. Thank you for your time, and your attention.

[akbarbmirza]

this change looks good to me but I would suggest adding some comments to explain this behavior and adding this limitation to a README for that sample so that people are explicitly aware that the sample is treating duplicate token names like this.