Properly install the LV2 targets

Closes surge-synthesizer#5014

CMakeLists.txt

@@ -1197,7 +1197,7 @@ if( UNIX AND NOT APPLE)
     # but you can't because surge-xt_VST3 points to the .so inside the VST3 bundle so instead say
     install( DIRECTORY "${SURGE_XT_OUTPUT_DIR}/VST3/Surge XT.vst3" DESTINATION lib/vst3 )
     if( JUCE_SUPPORTS_LV2 )
-      install(TARGETS surge-xt_LV2 DESTINATION lib/lv2 )
+      install(DIRECTORY "${SURGE_XT_OUTPUT_DIR}/LV2/Surge XT.lv2" DESTINATION lib/lv2 )
     endif()
   endif()
   if( BUILD_SURGE_EFFECTS_BANK )
@@ -1207,7 +1207,7 @@ if( UNIX AND NOT APPLE)
     install( DIRECTORY "${SURGE_FX_OUTPUT_DIR}/VST3/Surge XT Effects.vst3" DESTINATION lib/vst3 )
 
     if( JUCE_SUPPORTS_LV2 )
-      install(TARGETS surge-fx_LV2 DESTINATION lib/lv2)
+      install( DIRECTORY "${SURGE_FX_OUTPUT_DIR}/LV2/Surge XT Effects.lv2" DESTINATION lib/lv2 )
     endif()
   endif()
   install(DIRECTORY ${CMAKE_SOURCE_DIR}/resources/data/ DESTINATION share/surge-xt)

README.md

@@ -243,6 +243,13 @@ cmake -Bbuild -G"Visual Studio 15 2017"
 
 ### Building a Mac Fat Binary (ARM/Intel)
 
+To build a fat binary on a mac, simply add the following CMAKE argument to your intiial cmake run.
+
+```
+-D"CMAKE_OSX_ARCHITECTURES=arm64;x86_64"
+```
+
+
 ### Building for Raspberry Pi
 
 To build for a Raspberry Pi, you want to add the `LINUX_ON_ARM` CMake variable when you first run CMake. Otherwise,
@@ -262,6 +269,9 @@ cmake -Bignore/xc64 -DCMAKE_TOOLCHAIN_FILE=cmake/linux-aarch64-ubuntu-crosscompi
 cmake --build ignore/xc64 --config Debug --target surge-headless
 ```
 
+Of course that toolchain makes specific choices. You can make other choices as long as (1) you set the CMAKE
+variable LINUX_ON_ARM and (2) you make sure your host and your target compiler are both 64 bit.
+
 # Setting up for Your OS
 
 ## Windows