docs: make MkDocs site user-focused

- Diverge docs/index.md from README.md (remove dev content)
- Add docs/LICENCE.md, remove docs/contributing.md
- Update links: vyruss → pgEdge, DATA.md → docs/data.md
- Update mkdocs.yml navigation

Author: vyruss

README.md

@@ -146,7 +146,7 @@ $ ./radar -d mydatabase
 
 ## Data Collected
 
-For a complete reference of all collected data, see [DATA.md](DATA.md).
+For a complete reference of all collected data, see [docs/data.md](docs/data.md).
 
 **System Information**
 

docs/LICENCE.md

@@ -0,0 +1,9 @@
+The PostgreSQL License
+
+Portions copyright (c) 2025, pgEdge, Inc.
+
+Permission to use, copy, modify, and distribute this software and its documentation for any purpose, without fee, and without a written agreement is hereby granted, provided that the above copyright notice and this paragraph and the following two paragraphs appear in all copies.
+
+IN NO EVENT SHALL pgEdge, Inc. BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF pgEdge, Inc. HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+pgEdge, Inc. SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN “AS IS” BASIS, AND pgEdge, Inc. HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.