Use cmake_layout to support multiconfig

Author: ericriff

README.md

@@ -66,7 +66,7 @@ Assuming that you are in the **root** directory of `BehaviorTree.CPP`:
 ```
 mkdir build_release
 conan install . -of build_release -s build_type=Release --build=missing
-cmake -S . -B build_release -DCMAKE_TOOLCHAIN_FILE="build_release/conan_toolchain.cmake"
+cmake -S . -B build_release -DCMAKE_TOOLCHAIN_FILE="build_release/build/Release/generators/conan_toolchain.cmake"
 cmake --build build_release --parallel
 ```
 

conanfile.py

@@ -1,5 +1,5 @@
 from conan import ConanFile
-from conan.tools.cmake import CMakeToolchain, CMakeDeps
+from conan.tools.cmake import CMakeToolchain, CMakeDeps, cmake_layout
 
 class BehaviortreeCppConan(ConanFile):
     name = "behaviortree.cpp"
@@ -9,6 +9,9 @@ class BehaviortreeCppConan(ConanFile):
         "flatbuffers/*:header_only": True,
     }
 
+    def layout(self):
+        cmake_layout(self)
+
     def build_requirements(self):
        self.test_requires("gtest/1.14.0")