Fix file header
-# Hierarchical grid functions
+---
+id: hierarchy
+title: Hierarchical grid functions
+sidebar_label: Hierarchy
+slug: /api/hierarchy
+---
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
These functions permit moving between resolutions in the H3 grid system. The functions produce parent (coarser) or children (finer) cells.
