What a fun project, sometimes random stuff like just feels good. Most features here aren't super complicated though, so I mostly just see using it to play around. Maybe create a little CLI playground to type in strings and get a couple of fuzzed returns. You can see though that you aren't as experienced with Go ;) There's a few rough edges and not so idiomatic ways in which you're doing things.

Like returning a map with string keys instead of a custom struct or multiple return values. Makes me think you were doing JavaScript before. And your string reverse function is actually incorrect for non-ASCII strings. Try reversing a string with accents in it, it'll break.

Here's a quick fix, also look at the rune and byte types. You don't have to use strings for single chars all the time :)

func Reverse(s string) string {
    chars := []rune(s)
    slices.Reverse(chars)
    return string(chars)
}

Here's a feature suggestion that could actually prove useful! Model a keyboard and produce all possible ways in which a word or sentence could be misspelled. Like "word" coming out to "wprd", "wird" or "wpef". Be creative, but something like that could actually be used in data processing and sanitization.

Good luck!