Added docs for trigger interface

docs/book/how-to/build-pipelines/compose-pipelines.md

@@ -1,8 +1,8 @@
 ---
-description: Compose your ZenML pipelines.
+description: Reuse steps between pipelines.
 ---
 
-# Compose pipelines (reuse steps between pipelines)
+# Compose pipelines
 
 Sometimes it can be useful to extract some common functionality into separate functions
 in order to avoid code duplication. To facilitate this, ZenML allows you to compose your pipelines:
@@ -30,9 +30,7 @@ def training_pipeline():
 ```
 
 {% hint style="info" %}
-Calling a pipeline inside another pipeline does not actually trigger a separate run of the child pipeline
-but instead invokes the steps of the child pipeline to the parent pipeline. In order to trigger a pipeline
-from another, see [here](../trigger-pipelines/trigger-a-pipeline-from-another.md)
+Here we are calling one pipeline from within another pipeline, so functionally the data_loading_pipeline is functioning as a step within the training_pipeline though when it runs it is executing as an entirely separate pipeline. These two pipelines will be visible as separate pipelines within the ZenML dashboard, but practically they are working together within the umbrella of the training_pipeline. In order to trigger a pipeline from another, see [here](../trigger-pipelines/trigger-a-pipeline-from-another.md)
 {% endhint %}
 
 <table data-view="cards"><thead><tr><th></th><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td>Learn more about orchestrators here</td><td></td><td></td><td><a href="../../component-guide/orchestrators/orchestrators.md">orchestrators.md</a></td></tr></tbody></table>

docs/book/how-to/build-pipelines/configuring-a-pipeline-at-runtime.md

@@ -5,16 +5,15 @@ description: Configuring a pipeline at runtime.
 # Runtime configuration of a pipeline run
 
 It is often the case that there is a need to run a pipeline with a different configuration.
-In this case, you should in most cases use the `pipeline.with_options` method.  You can do
-this:
+In this case, you should in most cases use the [`pipeline.with_options`](../use-configuration-files/README.md) method. You can do this:
 
 1. Either by explicitly configuring options like `with_options(steps="trainer": {"parameters": {"param1": 1}})`
 2. Or by passing a YAML file using `with_options(config_file="path_to_yaml_file")`.
 
 You can learn more about these options [here](../use-configuration-files/README.md).
 
-However, there is one exception: If you would like to trigger a pipeline from the client
-or another pipeline, you would need to pass the PipelineRunConfiguration object.
+However, there is one exception: if you would like to trigger a pipeline from the client
+or another pipeline, you would need to pass the `PipelineRunConfiguration` object.
 Learn more about this [here](../trigger-pipelines/trigger-a-pipeline-from-another.md).
 
 <table data-view="cards"><thead><tr><th></th><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td>Using config files</td><td></td><td></td><td><a href="../use-configuration-files/README.md">../use-configuration-files/README.md</a></td></tr></tbody></table>