Extending the polish_names() function

[CyuHat]

Hi!
Thank you for your nice package. I think it is a nice and useful implementation janitor in Julia.

As a Follow up to the conversation I had with kdpsingh from the TidierData.jl package, I wanted to know if you are open to improve the polish_names() function in your package to match some specificities of the janitor::clean_names() function from R. Mainly the following points:

• Removing/replacing accents (à, é, ô, ...)
• Removing single and double quotes
• Removing various brackets
• Replacing "%" by "percent"
• Replacing "#" by "number"
• Removing other special characters ("!", ",", "$", ...)
• Appending numbers to duplicate names (if needed)

I am still a beginner, but I can give a hand for the implementation as it will help me gain more experiences with Julia.

[TheRoniOne]

Fixed on version 1.1.0, check my PR for the details on how I did it if you are interested.