I want to write a function that takes a list of words and keys and outputs those keys as dictionary keys with any words starting with that letter attached.
How could this be achieved using simple python 3 code?

eg. takes `(['apples', 'apple', 'bananna', 'fan'], 'fad')`

returns `{'a' : ['apple', 'apples'], 'f' : ['fan']}`

so far i have tried:

```
def dictionary(words, char_keys)
char_keys = remove_duplicates(char_keys)
ret = {}
keys_in_dict = []
words = sorted(words)
for word in words:
    if word[0] in char_keys and word[0] not in keys_in_dict:   
        ret[word[0]] = word
        keys_in_dict.append(word[0])
    elif word[0] in keys_in_dict:
        ret[word[0]] += (word)
return ret

```

This gives kinda the right output but it the output is in a single string rather than a list of strings.(the def is not indented properly i know)