Resolve https://projekte.kosit.org/kosit/validator/-/issues/97 "Replace docsify from UI"

server/ui/docs/api.md

@@ -0,0 +1,51 @@
+---
+sidebar_position: 2
+---
+
+# API Usage
+
+The validation service listens to `POST`-requests to any server uri. You need to supply the xml/object to validate in
+the post body.
+The service expects a single plain input in the post body, e.g. `multipart/form-data` is not supported.
+
+Examples:
+
+* `cURL`
+
+```shell script
+curl --location --request POST 'http://localhost:8080' \
+--header 'Content-Type: application/xml' \
+--data-binary '@/target.xml'
+```
+
+* `java` (Apache HttpClient)
+
+```java
+HttpClient httpClient=HttpClientBuilder.create().build();
+        HttpPost postRequest=new HttpPost("http://localhost:8080/");
+        FileEntity entity=new FileEntity(Paths.get("some.xml").toFile(),ContentType.APPLICATION_XML);
+        postRequest.setEntity(entity);
+        HttpResponse response=httpClient.execute(postRequest);
+        System.out.println(IOUtils.toString(response.getEntity().getContent()));
+```
+
+* `javascript`
+
+```javascript
+var myHeaders = new Headers();
+myHeaders.append("Content-Type", "application/xml");
+
+var file = "<file contents here>";
+
+var requestOptions = {
+    method: 'POST',
+    headers: myHeaders,
+    body: file,
+    redirect: 'follow'
+};
+
+fetch("http://localhost:8080", requestOptions)
+    .then(response => response.text())
+    .then(result => console.log(result))
+    .catch(error => console.log('error', error));
+```