[DOCS] optimizer header fix (#1545)

Author: mpytlik-intel

libraries/dl-streamer/docs/source/dev_guide/optimizer.md

@@ -17,12 +17,12 @@ Options:
     --log-level LEVEL                   Configure the logging detail level
 ```
 
-- Increasing the **search duration** will increase the chances of discovering more performant pipelines.  
-  -> Default: `300` seconds  
-- Increasing the **sample duration** will improve the stability of the search.  
-  -> Default: `10` seconds  
-- Available **log levels** are: CRITICAL, FATAL, ERROR, WARN, INFO, DEBUG.  
-  -> Default: `INFO`  
+- Increasing the **search duration** will increase the chances of discovering more performant pipelines.
+  -> Default: `300` seconds
+- Increasing the **sample duration** will improve the stability of the search.
+  -> Default: `10` seconds
+- Available **log levels** are: CRITICAL, FATAL, ERROR, WARN, INFO, DEBUG.
+  -> Default: `INFO`
 
 >Note: Search duration and sample duration both affect the amount of pipelines that will be explored during the search.
 ### Example
@@ -57,17 +57,17 @@ The easiest way of importing the optimizer into your scripts is to include it in
 
 Targets which are exported in order to facilitate usage inside of scripts:
 
-#### `preprocess_pipeline(pipeline) -> processed_pipeline` 
->`pipeline` - A string containing a valid DL Streamer pipeline.  
+### `preprocess_pipeline(pipeline) -> processed_pipeline`
+>`pipeline` - A string containing a valid DL Streamer pipeline.
 >`processed_pipeline` - A string containing the pipeline with all relevant substitutions.
 
 Perform quick search and replace for known combinations of elements with more performant alternatives.
 
-#### `get_optimized_pipeline(pipeline, search_duration, sample_duration) -> (optimized_pipeline, fps)`
->`pipeline` - A string containing a valid DL Streamer pipeline.  
->`search_duration` - The duration of searching for optimized pipelines in seconds, default `300`.  
->`sample_duration` - The duration of sampling each candidate pipeline in seconds, default `10`.  
->`optimized_pipeline` - A string containing the best performing pipeline that has been found during the search.  
+### `get_optimized_pipeline(pipeline, search_duration, sample_duration) -> (optimized_pipeline, fps)`
+>`pipeline` - A string containing a valid DL Streamer pipeline.
+>`search_duration` - The duration of searching for optimized pipelines in seconds, default `300`.
+>`sample_duration` - The duration of sampling each candidate pipeline in seconds, default `10`.
+>`optimized_pipeline` - A string containing the best performing pipeline that has been found during the search.
 >`fps` - The measured fps of the best perfmorming pipeline.
 
 Runs a series of optimization steps on the pipeline searching for a better performing versions.