fix typo in link

Author: behrends

docs/3-index-pages.md

@@ -8,7 +8,7 @@ Built in, Active Admin has the following index renderers:
 
 * *Table*: A table drawn with each row being a resource ([View Table Docs](3-index-pages/index-as-table.md))
 * *Grid*: A set of rows and columns each cell being a resource ([View Grid Docs](3-index-pages/index-as-grid.md))
-* *Blocks*: A set of rows (not tabular) each row being a resource ([View Blocks Docs](3-index-pages/index-as-blocks.md))
+* *Blocks*: A set of rows (not tabular) each row being a resource ([View Blocks Docs](3-index-pages/index-as-block.md))
 * *Blog*: A title and body content, similar to a blog index ([View Blog Docs](3-index-pages/index-as-blog.md))
 
 All index pages also support scopes, filters, pagination, action items, and