[Mlir-commits] [mlir] [mlir][sme] Update docs (PR #74527)

[Benjamin Maxwell]

================
@@ -1,13 +1,28 @@
 # 'ArmSME' Dialect
 
-[TOC]
+Basic dialect to target Arm SME.
+
+This dialect defines custom and LLVM IR intrinsic operations that are used to
+target Arm Scalable Matrix Extension. Through the available lowerings one can,
+for example, lower a [linalg.matmul](https://mlir.llvm.org/docs/Dialects/Linalg/#linalgmatmul-linalgmatmulop)
+opereation to Arm SME
+[FMOPA](https://developer.arm.com/documentation/ddi0602/2023-03/SME-Instructions/FMOPA--widening---Half-precision-floating-point-sum-of-outer-products-and-accumulate-)
+(floating point outer product) operations. See one of the in-tree end-to-end
----------------
MacDue wrote:

nit:
```suggestion
(floating-point outer product) operations. See one of the in-tree end-to-end
```

https://github.com/llvm/llvm-project/pull/74527