Fixes Incorrect Sidebar Links

Functions with the same name had the same id. For example, `lunr.Pipeline.load()`, `lunr.SortedSet.load()`, `lunr.Index.load()`, etc., all had `id='load'`, so every `href='#load'` link in the sidebar jumped to `lunr.Pipeline.load()`, because it was the first `id='load'` on the page. These changes give every identically named function a unique id, such as, `#Pipeline-load`, `#SortedSet-load`, and `#Index-load`, so that the sidebar behaves correctly.