Add 'Images of empowerment' as an external source

## Problem
The goal is to add a good number of external sources to give users a variety of results from different sources.

## Description
[Images of empowerment](https://www.imagesofempowerment.org/) is a free site where we can get images on women’s lives and work. it is also licensed under [Creative Commons Attribution-NonCommercial 4.0 International](https://creativecommons.org/licenses/by-nc/4.0/). Gotten from the additional sources list of Openverse available in the file [get-additional-sources.ts](https://github.com/WordPress/openverse-frontend/blob/main/src/utils/get-additional-sources.ts#L61) mentioned in https://github.com/creativecommons/search/issues/48

Adding Images of empowerment as an external source to CC search will be a good addition and will benefit our users by giving them more options.
## Alternatives

## Additional context

## Implementation

- [x] I would be interested in implementing this feature.

Start by reading src/utils/get-additional-sources.ts, especially the existing additional-source entries. Add Images of Empowerment following the file’s conventions, including its website and Creative Commons licensing information from the issue. Done means the source appears in the CC Search additional sources list.

Written by the indexing model from the issue text.