Adding Theme support

# Description

Implament a simple ui theme setting in either the top bar or bottom bar that allows users to select between a dark theme or a light theme. Also adding a folder themes that should contain all themes created for this.

# tasks

- [ ] Create a `themes/` directory to store all theme metadata.
- [ ] Add a ui element to select the theme.
- [ ] Add the selector in the javascript so that it actually changes the editor theme.
- [ ] Ensure that the themes either persist `(Optional)` on each use or offer clean application.

# Build steps

Once your changes are complete, Please make sure you have node js installed. If so please run
```dos
npm install
```
This will install all needed npm packages. Then run
```dos
npm run dist:win
```
This command packs the installer. Though this step is optional because for quick testing you will want to run
```dos
npm start
```

After you complete this please in the same PR update the file CONTRIBUTORS.md with your details if you would like to be acknowledged