doc: Fix typos

doc/userguide/configuration/suricata-yaml.rst

@@ -264,7 +264,7 @@ different YAML file.
   ...
 
 If the same section, say outputs is later redefined after the include
-statement it will overwrite the included file. Therefor any include
+statement it will overwrite the included file. Therefore any include
 statement at the end of the document will overwrite the already
 configured sections.
 

doc/userguide/rules/datasets.rst

@@ -4,7 +4,7 @@ Datasets
 Using the ``dataset`` and ``datarep`` keyword it is possible to match on
 large amounts of data against any sticky buffer.
 
-For example, to match against a DNs black list called ``dns-bl``::
+For example, to match against a DNS black list called ``dns-bl``::
 
     dns.query; dataset:isset,dns-bl;