Add brief description of dialects doc section.

Reviewed By: jpienaar

Differential Revision: https://reviews.llvm.org/D93466

diff --git a/mlir/docs/Dialects/_index.md b/mlir/docs/Dialects/_index.md
new file mode 100644 (file)
index 0000000..da19ddc
--- /dev/null
+++ b/mlir/docs/Dialects/_index.md
@@ -0,0 +1,6 @@
+# Dialects
+
+This section contains documentation for core and contributed dialects available
+from the MLIR repository. The description for each dialect includes content
+automatically generated from the dialect's
+[Operation Definition Specification (ODS)](../OpDefinitions.md).