[ENH] Getting started for query

docs/public_nodes.md

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+The public query tool at [query.neurobagel.org](https://query.neurobagel.org)
+queries the public Neurobagel federation API at [federate.neurobagel.org](https://federate.neurobagel.org)
+which provides access to all publicly accessible Neurobagel nodes.
+
+To start running your own cohort queries, 
+all you have to do is visit [query.neurobagel.org](https://query.neurobagel.org),
+enter your cohort criteria into the web interface, and click the "Submit" button.
+
+## Public Neurobagel Nodes
+
+At the moment, the following public Neurobagel nodes are available:
+
+- **OpenNeuro**. This node contains a (growing) subset of the datasets on [OpenNeuro](https://openneuro.org/). 
+  You can query this node by selecting the "OpenNeuro" option in the query tool.
+  The datasets you can find in this node have been annotated by the community and live in the
+  [OpenNeuroDatasets-JSONLD](https://github.com/OpenNeuroDatasets-jsonld) GitHub organization.
+- **International Neuroimaging Data-sharing Initiative** (INDI): This node contains public datasets from the [INDI](https://fcon_1000.projects.nitrc.org/) project.
+  You can query this node by selecting the "INDI" option in the query tool.
+  At the moment, the following datasets are queryable in the INDI node:
+    - [ABIDE 1](https://fcon_1000.projects.nitrc.org/indi/abide/abide_I.html)
+    - [ABIDE 2](https://fcon_1000.projects.nitrc.org/indi/abide/abide_II.html)
+    - [ADHD 200](https://fcon_1000.projects.nitrc.org/indi/adhd200/)
+    - [Consortium for Reliability and Reproducibility](https://fcon_1000.projects.nitrc.org/indi/CoRR/html/) (CoRR) datasets.
+- **Quebec Parkinson Network**: This node contains the [Quebec Parkinson Network](https://rpq-qpn.ca/en/home/) datasets.
+  Unlike the other two public nodes, the Quebec Parkinson Network node will not return participant level details.
+
+All nodes except for the Quebec Parkinson Network node allow you to download both participant-level information
+and the corresponding imaging data (where available) for the cohorts you search. 
+Downloading of imaging data is performed via [datalad](https://rpq-qpn.ca/en/home/).
+
+## Private Neurobagel nodes
+
+Nodes that are not purposefully made public are not accessible 
+outside of the institute or network where they are deployed.
+If you are interested in deploying a Neurobagel node for your institution,
+please refer to our [deployment documentation](./getting_started.md) for more information.

mkdocs.yml

@@ -25,12 +25,14 @@ nav:
   - Welcome: "index.md"
   - User guide:
     - Overview: "overview.md"
-    - How to run cohort queries: "query_tool.md"
+    - Running cohort queries:
+        - Search the public nodes: "public_nodes.md"
+        - How to use the query tool: "query_tool.md"
+        - Querying the API directly: "api.md"
     - Setting up your own Neurobagel node:
         - Getting started: "getting_started.md"
         - Configuring a node: "config.md"
         - Maintaining a node: "maintaining.md"
-        - Using the API directly: "api.md"
     - Annotating your data:
         - Preparing data for annotation: "data_prep.md"
         - Annotation tool guide: "annotation_tool.md"