Indexing Windows Libaries

Does the Windows Indexing feature include locations added to the 'library folders' automatically or do they have to be added?

It's automatic, but some options of what is indexed can be changed by the user. Since indexing is such an important function, I feel default is best. Most of MS articles are hard to decipher but the one on indexing explains it well. Search indexing in Windows 10: FAQ - Microsoft Support