Fix plugin validator errors

* all links in README.md should be absolute
* added screenshots to plugin.json
* fixed typo in link

Author: BenediktSeidl

README.md

@@ -16,14 +16,16 @@ interface as the Enterprise Edition has a more comprehensive filtering engine.
 Please consult the chapter ["Integrating Checkmk in Grafana"][3] in the
 official Checkmk documentation on how to use this plugin.
 
-![Checkmk Grafana Data Source Plugin](../assets/grafana-checkmk-datasource.png)
+![Checkmk Grafana Data Source Plugin](https://github.com/tribe29/grafana-checkmk-datasource/raw/ebf24142922ccce5cc5649aa4809d1c19d55958f/grafana-checkmk-datasource.png)
 
-See [CHANGELOG.md](CHANGELOG.md) for information about updating from previous
+See [CHANGELOG.md][4] for information about updating from previous
 versions.
 
-See [DEVELOPMENT.md](DEVELOPMENT.md) for information about how to build and
+See [DEVELOPMENT.md][5] for information about how to test, build and
 release this software.
 
 [1]: https://grafana.com/grafana/
 [2]: https://grafana.com/docs/grafana/latest/datasources/
 [3]: https://docs.checkmk.com/latest/en/grafana.html
+[4]: https://github.com/tribe29/grafana-checkmk-datasource/blob/main/CHANGELOG.md
+[5]: https://github.com/tribe29/grafana-checkmk-datasource/blob/main/DEVELOPMENT.md

src/plugin.json

@@ -17,9 +17,14 @@
     },
     "links": [
       { "name": "GitHub", "url": "https://github.com/tribe29/grafana-checkmk-datasource" },
-      { "name": "checkmk", "url": "https://checkmk.com" }
+      { "name": "Checkmk", "url": "https://checkmk.com" }
+    ],
+    "screenshots": [
+      {
+        "name": "Checkmk metrics shown in Grafana",
+        "path": "https://github.com/tribe29/grafana-checkmk-datasource/raw/ebf24142922ccce5cc5649aa4809d1c19d55958f/grafana-checkmk-datasource.png"
+      }
     ],
-    "screenshots": [],
     "version": "%VERSION%",
     "updated": "%TODAY%"
   },