docs(mac): improve documentation for mac build (#1873)

* docs(mac): Improve documentation for mac build

- added documentation to build from current master
- added troubleshooting information

Signed-off-by: Sebastian <tauven@gmail.com>

* docs(max): fix typo

Signed-off-by: Sebastian <tauven@gmail.com>

---------

Signed-off-by: Sebastian <tauven@gmail.com>

docs/content/docs/getting-started/build.md

@@ -45,6 +45,8 @@ To install the dependencies follow the instructions below:
 {{< tabs tabTotal="3"  >}}
 {{% tab tabName="Apple" %}}
 
+Install `xcode` from the App Store
+
 ```bash
 brew install abseil cmake go grpc protobuf wget
 ```
@@ -111,10 +113,12 @@ docker run --rm -ti -p 8080:8080 -e DEBUG=true -e MODELS_PATH=/models -e THREADS
 
 ### Example: Build on mac
 
-Building on Mac (M1 or M2) works, but you may need to install some prerequisites using `brew`. 
+Building on Mac (M1, M2 or M3) works, but you may need to install some prerequisites using `brew`. 
 
 The below has been tested by one mac user and found to work. Note that this doesn't use Docker to run the server:
 
+Install `xcode` from the Apps Store (needed for metalkit)
+
 ```
 # install build dependencies
 brew install abseil cmake go grpc protobuf wget
@@ -146,8 +150,20 @@ curl http://localhost:8080/v1/chat/completions -H "Content-Type: application/jso
    }'
 ```
 
-### Build with Image generation support
+#### Troublshooting mac
 
+If you encounter errors regarding a missing utility metal, install `Xcode` from the App Store.
+If completions are slow, ensure that `gpu-layers` in your model yaml matches the number of layers from the model in use (or simply use a high number such as 256).
+If you a get a compile error: `error: only virtual member functions can be marked 'final'`, reinstall all the necessary brew packages, clean the build, and try again.
+
+```
+# reinstall build dependencies
+brew reinstall abseil cmake go grpc protobuf wget
+
+make clean
+
+make build
+```
 
 **Requirements**: OpenCV, Gomp
 
@@ -239,13 +255,12 @@ make BUILD_TYPE=sycl_f32 build # for float32
 #### Metal (Apple Silicon)
 
 ```
-make BUILD_TYPE=metal build
+make build
 
-# Set `gpu_layers: 1` to your YAML model config file and `f16: true`
-# Note: only models quantized with q4_0 are supported!
+# correct build type is automatically used on mac (BUILD_TYPE=metal)
+# Set `gpu_layers: 256` (or equal to the number of model layers) to your YAML model config file and `f16: true`
 ```
 
-
 ### Windows compatibility
 
 Make sure to give enough resources to the running container. See https://github.com/go-skynet/LocalAI/issues/2