Instead of spdlog's bundled fmt re-use it from CPM.cmake (#364)

* Instead of spdlog's bundled fmt re-use it from CPM.cmake

* Add comment about re-using fmt for spdlog

* Update examples/spdlog/CMakeLists.txt

Co-authored-by: Lars Melchior <TheLartians@users.noreply.github.com>

* run cmake-format

* disable cmake-format around code block

Co-authored-by: Lars Melchior <TheLartians@users.noreply.github.com>

Author: jhasse

examples/spdlog/CMakeLists.txt

@@ -8,6 +8,20 @@ include(../../cmake/CPM.cmake)
 
 CPMAddPackage("gh:gabime/spdlog@1.8.2")
 
+# spdlog uses fmt and bundles that dependency. If you want to use fmt in your project as well, you
+# can let spdlog re-use fmt from CPM.cmake like this:
+#
+# cmake-format: off
+#
+# CPMAddPackage("gh:fmtlib/fmt#7.1.3") 
+# CPMAddPackage(
+#   GITHUB_REPOSITORY gabime/spdlog 
+#   VERSION 1.8.2 
+#   OPTIONS "SPDLOG_FMT_EXTERNAL 1" 
+# )
+#
+# cmake-format: on
+
 # ---- Executable ----
 
 add_executable(CPMSpdlogExample main.cpp)