Update invocation methods in workflow guide

The workflow invocation guide was updated to provide more clarity and richness. Improvements were made to the listed methods of invoking workflows, with added hyperlinks for ease of navigation. Sections on how to use the Elsa REST API and Elsa library were introduced, providing examples and detailed instructions to aid better understanding. Minor text edits were also made to enhance clarity.

writerside/topics/Invoking-Workflows.topic

@@ -12,11 +12,11 @@
     </p>
 
     <list>
-        <li><a href="#using-elsa-studio">Using Elsa Studio.</a></li>
+        <li><a href="#using-elsa-studio">Using Elsa Studio</a>.</li>
         <li><a href="#using-triggers">Using a trigger, such as <control>HTTP Endpoint</control></a>.</li>
-        <li>Using activities such as <control>Dispatch Workflow</control></li>
-        <li>Using the ELSA REST API.</li>
-        <li>Using C# code using the workflow runtime service, workflow inbox or workflow dispatcher.</li>
+        <li><a href="#using-dispatch-workflow-activity">Using activities such as <control>Dispatch Workflow</control><a/>.</li>
+        <li><a href="#using-elsa-rest-api">Using the ELSA REST API</a>.</li>
+        <li><a href="using-elsa-library">Using the Elsa library</a>.</li>
     </list>
 
     <p>In this guide, we will see an example of each of these methods.</p>
@@ -222,7 +222,7 @@
                     <code-block lang="curl">
                         curl --location 'https://localhost:5001/workflows/hello-world'
                     </code-block>
-                    <p>And since this is a simple GET request, we can of course paste the URL straight into the browser:</p>
+                    <p>And since this is a simple GET request, we can paste the URL straight into the browser:</p>
                     <img src="using-http-trigger-browser.png" alt="Invoking the workflow via the browser" thumbnail="false" border-effect="rounded"/>
                 </step>
                 <p>The HTTP Endpoint activity offers a simple yet effective way to trigger workflows via HTTP requests.</p>
@@ -280,6 +280,34 @@
                 <p>The Dispatch Workflow activity offers a simple way to invoke a workflow from another workflow.</p>
             </procedure>
         </chapter>
+        <chapter title="Elsa REST API" id="using-elsa-rest-api">
+            <p>When setting up Elsa Server from the <a href="Elsa-Server.topic">installation guide</a>, it will include the Elsa API module which exposes API endpoints.</p>
+            <p>These endpoints are consumed by <a href="Elsa-Studio.topic">Elsa Studio</a>, but can also be used by your own application and from other HTTP clients such as <a href="https://www.postman.com/">Postman</a>.</p>
+            <p>One of these endpoints provides the ability to start a workflow.</p>
+            <p>The following curl shows an example that starts a workflow:</p>
+            <code-block lang="curl">
+                curl --location --request POST 'https://localhost:5001/elsa/api/workflow-definitions/{workflow-definition-id}/execute' \
+                --header 'Authorization: ApiKey {your-api-key}'
+            </code-block>
+        </chapter>
+        <chapter title="Elsa Library" id="using-elsa-library">
+            <p>It is also possible to programmatically execute workflows from within the Elsa Server itself. For example, you could have a custom API controller from which you want to invoke a specific workflow</p>
+            <p>Elsa offers various services, ranging from general-purpose low-level services such as <code>IWorkflowRunner</code> to opinionated high-level services such as <code>IWorkflowRuntime</code></p>.
+            <p>The right service to use depends on your use case. When you have a workflow definition ID that you want to execute immediately, use the <code>IWorkflowRuntime</code> service:</p>
+            <code-block lang="c#">
+                await _workflowRuntime.StartWorkflowAsync(definitionId);
+            </code-block>
+            <p>If you want to execute a workflow asynchronously and not wait for it to start or complete, you can use <code>IWorkflowDispatcher</code>:</p>
+            <code-block lang="c#">
+                var dispatchRequest = new DispatchWorkflowDefinitionRequest
+                {
+                    DefinitionId = "your-definition-id",
+                    VersionOptions = VersionOptions.Published
+                };
+
+                await _workflowDispatcher.DispatchAsync(dispatchRequest);
+            </code-block>
+        </chapter>
     </chapter>
 
     <seealso>