docs: added sphinx base structure

docs/index.md

@@ -0,0 +1,37 @@
+# BEC Widgets documentation
+
+<br><br>
+
+````{grid} 3
+:gutter: 5
+
+```{grid-item-card}  Introduction
+:link: introduction
+:link-type: ref
+
+General information about BEC Widgets.
+```
+
+```{grid-item-card}  User
+:link: user
+:link-type: ref
+
+Information for users of BEC Widgets.
+```
+
+```{grid-item-card}  Developer
+:link: developer
+:link-type: ref
+
+Information for developers of BEC Widgets.
+```
+````
+
+
+```{toctree}
+:maxdepth: 2
+
+introduction/introduction
+user/user
+developer/developer
+```