A few example diagram...
<section data-markdown>
<textarea data-template>
## Diagram in Markdown
```plantuml
@startuml
Alice -> Bob: Authentication Request
Bob --> Alice: Authentication Response
Alice -> Bob: Another authentication Request
Alice <-- Bob: Another authentication Response
@enduml
```
</textarea>
</section>
<pre>
<code class="language-plantuml">
@startuml
User -> (Start)
User --> (Use the application) : A small label
:Main Admin: ---> (Use the application) : This is\nAnother\nlabel
@enduml
</code>
</pre>
@startuml
User -> (Start)
User --> (Use the application) : A small label
:Main Admin: ---> (Use the application) : This is\nAnother\nlabel
@enduml
Check README on GitHub for more information