typo: buy -> by (#55)

notebooks/foundations/01_kerchunk_basics.ipynb

@@ -79,7 +79,7 @@
     "In this example we are passing a few kwargs. In short they are:\n",
     "- `anon=True`: This is a `s3fs` kwarg that specifies you are not passing any connection credentials and are connecting to a public bucket.\n",
     "- `default_fill_cache=False`: `s3fs` kwarg that avoids caching in between chunks of files. This may lower memory usage when reading large files.\n",
-    "- `default_cache_type=\"first\"`: `fsspec` kwarg that specifies the caching strategy used buy `fsspec`. In this case, `first` caches the first block of a file only.\n",
+    "- `default_cache_type=\"first\"`: `fsspec` kwarg that specifies the caching strategy used by `fsspec`. In this case, `first` caches the first block of a file only.\n",
     "\n",
     "Don't worry too much about the details here; the cache options are those that have typically proven efficient for HDF5 files. "
    ]