fix doc headings. fixes apache#4702

docs/hop-user-manual/modules/ROOT/pages/how-to-guides/joins-lookups.adoc

@@ -22,7 +22,7 @@ under the License.
 
 Hop offers a lot of options to enrich and combine data, among other things through joins and lookups. This guide explains the differences between the various joins and lookups, and will help you to choose the right transform for your pipelines.
 
-=== Joins
+== Joins
 
 Joins are a way to merge data from two or more different streams in your pipeline. Joins typically require you to select a set of fields (the join keys) to join the streams on. The data in all streams that are involved in the join needs to be sorted on the join keys.
 
@@ -80,7 +80,7 @@ allows you to run a query against a database using data obtained from previous t
 
 |===
 
-=== Lookups
+== Lookups
 
 Lookups are a way to let you enrich your pipeline's stream with additional fields from external sources. The transforms allow you to choose which additional fields will be retrieved from the lookup source.
 
@@ -146,7 +146,7 @@ The stream lookup accepts data from any pipeline stream, but since the data need
 |===
 
 
-=== Lookup Caching
+== Lookup Caching
 
 The xref:pipeline/transforms/combinationlookup.adoc[Combination lookup/update], xref:pipeline/transforms/dimensionlookup.adoc[Dimension lookup/update] and xref:pipeline/transforms/databaselookup.adoc[Database lookup] allow you to cache data. Cached data is stored in memory to speed up the lookup process.
 

docs/hop-user-manual/modules/ROOT/pages/workflow/workflows.adoc

@@ -20,7 +20,7 @@ under the License.
 
 = Workflows
 
-=== Workflow overview
+== Workflow overview
 
 Workflows are one of the core building blocks in Apache Hop. Where pipelines do the heavy data lifting, workflows take care of the orchestration work: prepare the environment, fetch remote files, perform error handling and executing child workflows and pipelines.
 
@@ -35,7 +35,7 @@ Even though there is some visual resemblance, workflows and pipelines operate ve
 * Workflow actions do not pass data over hops. Each workflow action has a `success` or `failure` exit status. This exit status is used to choose the routing through the workflow.
 * Hops between actions in a workflow have a status: depending on the exit status of the previous action, a workflow hop can follow the success (green), failure (orange) or unconditional (black) hop. An unconditional hop ignores the exit status of the previous action and is followed whether the previous action failed or succeeded.
 
-=== Example workflow walk-through
+== Example workflow walk-through
 
 Like all workflows, the example workflow shown below starts with the `start` action.
 
@@ -51,7 +51,7 @@ If the temporary files are removed successfully, we move on to the "success" act
 
 image:hop-gui/workflow/basic-workflow.png[Workflows - basic workflows, width="65%"]
 
-=== Next steps
+== Next steps
 
 The following pages take you deeper into the process of building and running workflows: