Doesn't return index of keywords found in text

I've noticed that the implementation doesn't return the index of where keywords were found in text. This forces the user to do another search for the keyword to find its index, while the Aho Corasick algorithm should be able to provide this information for no extra cost.

I've made several modifications to the implementation in my fork https://github.com/issamemari/ahocorasick, among which is making the algorithm return the index the index. I'm happy to submit a PR that includes only the changes related to this.

Read the repository's current Aho-Corasick matching implementation and compare the fork linked in the issue, focusing on how keyword matches are returned. Done means callers receive the index of each keyword found in the text without performing a second search, while unrelated fork changes are excluded.

Written by the indexing model from the issue text.