Arm backend: Fix stale docgen generation pt.2 (pytorch#19685)

Port doc changes from 12bb0e7 from pure md-files to md.in stubs.


Signed-off-by: Adrian Lundell <adrian.lundell@arm.com>

Author: AdrianLundell

backends/arm/scripts/docgen/ethos-u/backends-arm-ethos-u-overview.md.in

@@ -153,7 +153,7 @@ ExecuTorch for the Ethos-U backend, you automatically install the compiler conta
 
 **→{doc}`/backends/arm-ethos-u/arm-ethos-u-troubleshooting` — Troubleshooting and common issues.**
 
-**→{doc}`/backends/arm-ethos-u/tutorials/arm-ethos-u-tutorials` — Tutorials.**
+**→{doc}`/backends/arm-ethos-u/tutorials/ethos-u-getting-started` — Getting started tutorial.**
 
 **→{doc}`/backends/arm-ethos-u/U55_op_support` — Ethos-U55 supported operators.**
 
@@ -168,7 +168,7 @@ ExecuTorch for the Ethos-U backend, you automatically install the compiler conta
 arm-ethos-u-partitioner
 arm-ethos-u-quantization
 arm-ethos-u-troubleshooting
-tutorials/arm-ethos-u-tutorials
+tutorials/ethos-u-getting-started
 U55_op_support
 U85_op_support
 ```

backends/arm/scripts/docgen/vgf/backends-arm-vgf-overview.md.in

@@ -79,7 +79,7 @@ described in the rest of this guide but with a concrete end-to-end sample.
 
 **→{doc}`/backends/arm-vgf/arm-vgf-troubleshooting` — Debug common issues.**
 
-**→{doc}`/backends/arm-vgf/tutorials/arm-vgf-tutorials` — Tutorials.**
+**→{doc}`/backends/arm-vgf/tutorials/vgf-getting-started` — Getting started tutorial.**
 
 **→{doc}`/backends/arm-vgf/VGF_op_support` — VGF supported operators.**
 
@@ -92,6 +92,6 @@ described in the rest of this guide but with a concrete end-to-end sample.
 arm-vgf-partitioner
 arm-vgf-quantization
 arm-vgf-troubleshooting
-tutorials/arm-vgf-tutorials
+tutorials/vgf-getting-started
 VGF_op_support
 ```

backends/arm/scripts/docgen/vgf/vgf-getting-started-tutorial.md.in

@@ -83,9 +83,9 @@ To produce a pte file equivalent to the one above, run
 `python -m backends.arm.scripts.aot_arm_compiler --model_name=add --delegate --quantize --output=simple_example.pte --target=vgf`
 ```
 
-### Runtime:
+## Runtime
 
-## Build executor runtime
+### Build executor runtime
 
 After the AOT compilation flow is done, we can build the executor runner target. For this tutorial, the default runner can be used. Build it with the following configuration:
 
@@ -115,7 +115,7 @@ The block diagram below demonstrates, at the high level, how the various build a
 ![](arm-delegate-runtime-build.svg)
 
 
-## Deploying and running on device
+### Deploying and running on device
 
 Since we are using the Vulkan emulation layer, we can run the executor runner with the VGF delegate on the host machine: