Tag Deletion

**Is your feature request related to a problem? Please describe.**

Yes, There are two tags with similar name, only one of the two is the right one but every time I tag a new note I keep in doubt about what is the right tag, then I have to check which tag is the right tag before use it.

**Describe the solution you'd like**

I want to delete tags that I don't need anymore or created by mistake.

First use case: I've created the `books` tag, then decided to name it `book`, there is no way to rename it, then I've created the second tag called `book`, I need to delete one of them to remove the dubious.

Second use case: Created a tag named `book` then forgot that I've created that tag and created `livro` (book in portuguese) , now I want to delete one of the two.

**Describe alternatives you've considered**

I have no alternative.