chatgui: invite link dialogs, zxing-cpp QR code, crypto transport, channel improvements; msg_transport: chat protocol support

tools/chatgui/zxing-cpp/docs/CMakeLists.txt

@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(ZXingDocs VERSION 3.1.0)
+
+find_package(Doxygen)
+
+if(DOXYGEN_FOUND)
+    include(FetchContent)
+    FetchContent_Declare(
+        doxygen-awesome-css
+        URL https://github.com/jothepro/doxygen-awesome-css/archive/refs/heads/main.zip
+        DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+    )
+    FetchContent_MakeAvailable(doxygen-awesome-css)
+
+    # Save the location the files were cloned into
+    # This allows us to get the path to doxygen-awesome.css
+    FetchContent_GetProperties(doxygen-awesome-css SOURCE_DIR AWESOME_CSS_DIR)
+
+    # Generate the Doxyfile
+    set(DOXYFILE_IN ${CMAKE_CURRENT_SOURCE_DIR}/Doxyfile.in)
+    set(DOXYFILE_OUT ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile)
+    configure_file(${DOXYFILE_IN} ${DOXYFILE_OUT} @ONLY)
+
+    add_custom_target(docs
+        COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYFILE_OUT}
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+        VERBATIM)
+endif()