Apply suggestions from code review

Co-authored-by: Daniil Gusev <daniil@quix.io>

Author: gwaramadze

docs/joins.md

@@ -115,7 +115,6 @@ if __name__ == '__main__':
 ```
 
 
-
 #### State expiration
 `StreamingDataFrame.join_asof` stores the right records to the state.  
 The `grace_ms` parameter regulates the state's lifetime (default - 7 days) to prevent it from growing in size forever.
@@ -131,6 +130,7 @@ Adjust `grace_ms` based on the expected time gap between the left and the right
 ### Limitations
 
 - Joining dataframes belonging to the same topics (aka "self-join") is not supported.
+- Join types "right" and "outer" are not supported.
 - As-of join preserves headers only for the left dataframe. If you need headers of the right side records, consider adding them to the value.
 
 ### Message ordering between partitions
@@ -283,7 +283,8 @@ The merging behavior is controlled by the `on_merge` parameter, which works the
 
 ### Limitations
 
-- Joining dataframes belonging to the same topics (aka "self-join") is not supported
-- The `backward_ms` must not be greater than the `grace_ms` to avoid losing data
+- Joining dataframes belonging to the same topic (aka "self-join") is not supported.
+- The `backward_ms` must not be greater than the `grace_ms` to avoid losing data.
 - Interval join does not preserve any headers. If you need headers from any side, consider adding them to the value.
-- Performance of the join depends on the density of the data. If streams on both sides move very fast (a lot of messages) then the performance may drop significantly.
+- The performance of the interval join depends on the density of the data.   
+If both streams have too many matching messages falling within the interval, the performance may drop significantly due to the large number of produced outputs.

quixstreams/dataframe/dataframe.py

@@ -1737,7 +1737,7 @@ def join_asof(
     def join_interval(
         self,
         right: "StreamingDataFrame",
-        how: Literal["inner", "left"] = "inner",
+        how: JoinHow = "inner",
         on_merge: Union[OnOverlap, Callable[[Any, Any], Any]] = "raise",
         grace_ms: Union[int, timedelta] = timedelta(days=7),
         name: Optional[str] = None,