[DOC] Add a reference to mendeleev-data repo

README.md

@@ -30,6 +30,18 @@ of elements, ions and isotopes in the periodic table of elements.
 </p>
 
 
+> [!TIP]
+> If you're looking for raw data behind ``mendeleev`` have a look at [mendeleev-data](https://github.com/lmmentel/mendeleev-data) repo.
+> 
+> You can find **all data assets** in multiple formats: 
+> - csv, 
+> - html,
+> - json, 
+> - sql,
+> - markdown.
+>
+> All releases a tagged with the same version numbers as ``mendeeleev``.
+
 <!-- TABLE OF CONTENTS -->
 ## Table of Contents
 

docs/source/data_access.rst

@@ -3,6 +3,20 @@
 Accessing data
 ==============
 
+.. tip::
+
+    If you're looking for raw data behind ``mendeleev`` have a look at `mendeleev-data <https://github.com/lmmentel/mendeleev-data>`_ repo.
+
+    You can find **all data assets** in multiple formats: 
+
+    - csv, 
+    - html,
+    - json, 
+    - sql,
+    - markdown.
+
+    All releases a tagged with the same version numbers as ``mendeeleev``.
+
 Individual Elements
 -------------------