docs: add doc block for getFilteredEntryPoints function

src/utils/get-filtered-entrypoints.js

@@ -1,3 +1,13 @@
+/**
+ * Get filtered entrypoints for projects.
+ * 
+ * Example command: build project1@entry1+entry2,project2@entry3
+ * Example input: 'project1@entry1+entry2,project2@entry3'
+ * Example return: { project1: ['entry1', 'entry2'], project2: ['entry3'] }
+ * 
+ * @param {Array} projects Projects of which to filter entrypoints for.
+ * @returns {object} An object with project keys of which value for each is the entrypoints to build.
+ */
 const getFilteredEntryPoints = (projects) => {
     const filteredProjectEntryPoints = {};
     const projectNames = projects.split(',');