Splits sentences into sentence parts based on stopwords.

@param {string} sentence The sentence to split.
@param {Array} stopwords The array with matched stopwords.
@returns {Array} The array with sentence parts.
function splitOnWords( sentence, stopwords ) {
	const splitSentences = [];

	// Split the sentence on each found stopword and push this part in an array.
	forEach( stopwords, function( stopword ) {
		const sentenceSplit = sentence.split( stopword );
		if ( ! isEmpty( sentenceSplit[ 0 ] ) ) {
			splitSentences.push( sentenceSplit[ 0 ] );
		}
		const startIndex = sentence.indexOf( stopword );
		const endIndex = sentence.length;
		sentence = stripSpaces( sentence.substr( startIndex, endIndex ) );
	} );

	// Push the remainder of the sentence in the sentence parts array.
	splitSentences.push( sentence );
	return splitSentences;
}