Improvement: add ability for numbers and special characters on passphrase

[catrone3]

As someone who mostly uses passphrases I like having the ability to add numbers and specified special characters to the generation. I am willing to work on this myself if you are ok with it, just wanting to make an issue tracking it incase you do not want anyone else contributing.

[remvze]

Hey there. I am open to contributors, but at the moment, I'm planning to make some changes (mostly design-related) to this project. So, we can either brainstorm on how to implement this feature, and I will add it myself while making the changes, or if you want to do it yourself, we can wait until I'm done, and then I'll ping you here to let you know when it's ready to be worked on. Let me know what you think.

[catrone3]

I am ok with either route, if you want to add it yourself while making the changes. My first thought as a rough thing is to have the checkboxes for including numbers and symbols show on the passphrase screen and just add them to either the end or the beginning. This would be a rough first start and looking at the code appears to be the fastest route.

A more in depth change would be to have the symbols be the word separators with an option to add them on add one or both ends along with the numbers being at one or both ends.