DOC: Add dev guide for building SA^M against static build of Autoscoper

Documentation/developer-guide/building-autoscoperm.md

@@ -8,7 +8,7 @@ Being an extension of 3D Slicer, the first step is to build Slicer from source.
 
 Once Slicer is built, the next step is to build AutoscoperM.
 
-* Clone the AutoscoperM respotory into its own directory:
+* Clone the AutoscoperM repository into its own directory:
     * `git clone https://github.com/BrownBiomechanics/SlicerAutoscoperM.git`
 * Create a build directory for AutoscoperM (it is recommended to do an out of source build):
     * `mkdir SlicerAutoscoperM-build`
@@ -22,3 +22,33 @@ Once Slicer is built, the next step is to build AutoscoperM.
 * Select a configuration type and build the project:
     * `cmake --build . --config Release`
 * Once the project is built, the extension can be loaded by launching the `SlicerWithSlicerAutoscoperM` executable located inside the `inner-build` folder in the build directory.
+
+
+## Building AutoscoperM Against an Existing Autoscoper Build
+
+If you have already built Autoscoper, you can build AutoscoperM against that build. This is useful if you don't want to build Autoscoper every time you build AutoscoperM.
+
+* The first step is to build Autoscoper. The instructions for building Autoscoper can be found in the [](./building-autoscoper.md).
+* Once Autoscoper is built, the next step is to build AutoscoperM.
+    * Clone the AutoscoperM repository into its own directory:
+        * `git clone https://github.com/BrownBiomechanics/SlicerAutoscoperM.git`
+    * Create a build directory for AutoscoperM (it is recommended to do an out of source build):
+        * `mkdir SlicerAutoscoperM-build`
+    * Configure the project with the `SlicerAutoscoperM_SUPERBUILD` option set to `OFF`:
+        * `cmake ../path/to/source/ -DSlicer_DIR=/path/to/Slicer-build/ -DQt5_DIR=/path/to/Qt5Config.cmake -DSlicerAutoscoperM_SUPERBUILD=OFF`
+    * Select a configuration type and build the project:
+        * `cmake --build . --config Release`
+* Next, you will need to create a custom launcher settings `ini` file as shown below:
+```ini
+[LibraryPaths]
+1\path=path/to/autoscoper-build/GLEW-install/bin
+2\path=path/to/autoscoper-build/TIFF-install/bin
+3\path=path/to/autoscoper-build/OpenCL-ICD-Loader-build/bin/{Release,Debug}
+size=3
+
+[Paths]
+1\path=path/to/autoscoper-build/Autoscoper-build/bin/{Release,Debug}
+size=1
+```
+* Launch Slicer with the custom launcher settings `ini` file:
+    * `SlicerWithSlicerAutoscoperM --launcher-additional-settings path/to/custom/launcher/settings.ini`