Update existing_data.md

added OpenAIRE Explore

pages/your_tasks/existing_data.md

@@ -42,6 +42,7 @@ Many datasets could exist that you can reuse for your project. Even if you know
     * {% tool "google-dataset-search" %} or {% tool "datacite" %} for localization of datasets.
     * The {% tool "omicsdi" %} provides a knowledge discovery framework across heterogeneous omics data (genomics, proteomics, transcriptomics and metabolomics).
     * The {% tool "elixir-core-data-resources" %} list of knowledge resources recommended by ELIXIR.
+    * {% tool "openaire-explore" %} provides linked open research datasets.
 
 * Search through all repositories you found to identify what you could use. Give priority to curated repositories.