Update README.md

Author: royshil

README.md

@@ -29,6 +29,41 @@ Install dependencies:
 $ brew install opencv onnxruntime
 ```
 
+#### Finding libobs
+
+If you install OBS app you already have the binaries for libobs (e.g. `/Applications/OBS.app/Contents/Frameworks/libobs.0.dylib`)
+But you don't have the headers - so clone the main obs repo e.g. `git clone [email protected]:obsproject/obs-studio.git`
+
+Then you'd need to point `FindLibObs.cmake` to find the lib and headers:
+```
+find_path(LIBOBS_INCLUDE_DIR
+	NAMES obs.h
+	HINTS
+		ENV obsPath${_lib_suffix}
+		ENV obsPath
+		${obsPath}
+	PATHS
+		/Users/roy_shilkrot/Downloads/obs-studio/libobs/
+		/usr/include /usr/local/include /opt/local/include /sw/include
+	PATH_SUFFIXES
+		libobs
+	)
+```
+and
+```
+	find_library(${base_name_u}_LIB
+		NAMES ${_${base_name_u}_LIBRARIES} ${lib_name} lib${lib_name} ${lib_name}.0
+		HINTS
+			ENV obsPath${_lib_suffix}
+			ENV obsPath
+			${obsPath}
+			${_${base_name_u}_LIBRARY_DIRS}
+		PATHS
+			/Applications/OBS.app/Contents/Frameworks
+			/usr/lib /usr/local/lib /opt/local/lib /sw/lib
+# ...
+```
+
 Build:
 ```
 $ mkdir build && cd build