Fix spelling errors (dask#2382)

Author: jbcrail

docs/source/array-creation.rst

@@ -149,7 +149,7 @@ Unknown Chunks
 
 Some arrays have unknown chunk sizes.  These are designated using ``np.nan``
 rather than an integer.  These arrays support many but not all operations.  In
-particular, opeations like slicing are not possible and will result in an
+particular, operations like slicing are not possible and will result in an
 error.
 
 .. code-block:: python

docs/source/dataframe-create.rst

@@ -97,7 +97,7 @@ From Raw Dask Graphs
 This section is mainly for developers wishing to extend dask.dataframe.  It
 discusses internal API not normally needed by users.  Everything below can be
 done just as effectively with :doc:`dask.delayed<delayed-overview>`  described
-just above.  You should never need to create a dataframe object by han
+just above.  You should never need to create a dataframe object by hand.
 
 To construct a DataFrame manually from a dask graph you need the following
 information:

docs/source/dataframe-design.rst

@@ -81,7 +81,7 @@ Dask dataframe divides `categorical data`_ into two types:
   different categories in each partition.  Internally, unknown categoricals are
   indicated by the presence of ``dd.utils.UNKNOWN_CATEGORIES`` in the
   categories on the ``_meta`` attribute.  Since most dataframe operations
-  propogate the categories, the known/unknown status should propogate through
+  propagate the categories, the known/unknown status should propagate through
   operations (similar to how ``NaN`` propagates).
 
 For metadata specified as a description (option 2 above), unknown categoricals

docs/source/remote-data-services.rst

@@ -148,7 +148,7 @@ The following parameters may be passed to s3fs using ``storage_options``:
 
     - token: if authentication has been done with some other S3 client
 
-    - use_ssl: whether connections are encryted and secure (default True)
+    - use_ssl: whether connections are encrypted and secure (default True)
 
     - client_kwargs: dict passed to the `boto3 client`_, with keys such
       as `region_name`, `endpoint_url`