Add ESP-IDF component support

- Add idf_component.yml for ESP Component Registry
- Add ESP_PLATFORM detection in CMakeLists.txt

Author: cleishm

CMakeLists.txt

@@ -1,12 +1,18 @@
 cmake_minimum_required(VERSION 3.14)
 
 project(frequency
-    VERSION 1.0.0
+    VERSION 1.1.0
     DESCRIPTION "Type-safe frequency handling library modeled after std::chrono"
     HOMEPAGE_URL "https://github.com/cleishm/frequency-cpp"
     LANGUAGES CXX
 )
 
+# ESP-IDF component support
+if(ESP_PLATFORM)
+    idf_component_register(INCLUDE_DIRS "include")
+    return()
+endif()
+
 option(FREQUENCY_BUILD_TESTS "Build tests" ${frequency_IS_TOP_LEVEL})
 
 set(CMAKE_CXX_EXTENSIONS OFF)

idf_component.yml

@@ -0,0 +1,12 @@
+version: "1.1.0"
+description: "Type-safe frequency handling library modeled after std::chrono"
+url: "https://github.com/cleishm/frequency-cpp"
+repository: "https://github.com/cleishm/frequency-cpp.git"
+license: "MIT"
+targets:
+  - esp32
+  - esp32s2
+  - esp32s3
+  - esp32c3
+  - esp32c6
+  - esp32h2