[mlir][ArmSME] Switch to using custom documentation

This patch introduces a hand-written markdown file that documents the
ArmSME dialect. ATM, it simply includes the auto-generated documentation
for the custom and for the LLVM intrinsic ops. Doing this by hand allows
us to clarify the document by splitting it into meaningful categories.

Moving forward, this change will allow us to improve/expand the
documentation for the ArmSME dialect (and, in general, about supporting
SME in MLIR).

Depends on #67985

Author: banach-space

mlir/docs/Dialects/ArmSME.md

@@ -0,0 +1,16 @@
+# 'ArmSME' Dialect
+
+Basic dialect to target Arm SME architectures This dialect contains the
+definitions necessary to target Arm SME scalable matrix operations.
+
+## References
+* https://developer.arm.com/documentation/ddi0616
+* https://developer.arm.com/documentation/ddi0602/2023-03/SME-Instructions
+
+## Operations
+
+[include "Dialects/ArmSMEOps.md"]
+
+## Operations for LLVM IR Intrinsics
+
+[include "Dialects/ArmSMEIntrinsicOps.md"]

mlir/include/mlir/Dialect/ArmSME/IR/CMakeLists.txt

@@ -1,5 +1,4 @@
 add_mlir_dialect(ArmSME arm_sme ArmSME)
-add_mlir_doc(ArmSME ArmSME Dialects/ -gen-dialect-doc -dialect=arm_sme)
 
 # Generate declarations and definitions of ArmSME Ops
 set(LLVM_TARGET_DEFINITIONS ArmSMEOps.td)
@@ -22,3 +21,7 @@ mlir_tablegen(ArmSMEIntrinsicOps.h.inc -gen-op-decls)
 mlir_tablegen(ArmSMEIntrinsicOps.cpp.inc -gen-op-defs)
 mlir_tablegen(ArmSMEIntrinsicConversions.inc -gen-llvmir-conversions)
 add_public_tablegen_target(MLIRArmSMEIntrinsicOpsIncGen)
+
+# Generate the docs
+add_mlir_doc(ArmSMEOps ArmSMEOps Dialects/ -gen-op-doc)
+add_mlir_doc(ArmSMEIntrinsicOps ArmSMEIntrinsicOps Dialects/ -gen-op-doc)