Update md files. Add cpp in docs/examples (#1769)

* Update md files. Add cpp in docs/examples

* Normalize all the line endings

* Fix block_id in snippets

* Fix utf-8 encoding

* Add new folder for snippets

* Fix issues with compiling code from snippets

* Added conteiner iterator fix

docs/snippets/MULTI1.cpp

@@ -0,0 +1,24 @@
+#include <inference_engine.hpp>
+#include <multi-device/multi_device_config.hpp>
+
+
+int main() {
+using namespace InferenceEngine;
+//! [part1]
+    Core ie; 
+    auto network = ie.ReadNetwork("sample.xml");
+    ExecutableNetwork exec = ie.LoadNetwork(network, "MULTI:HDDL,GPU", {});
+    //...
+    exec.SetConfig({{"MULTI_DEVICE_PRIORITIES", "GPU,HDDL"}});
+    // you can even exclude some device
+    exec.SetConfig({{"MULTI_DEVICE_PRIORITIES", "GPU"}});
+    //...
+    // and then return it back
+    exec.SetConfig({{"MULTI_DEVICE_PRIORITIES", "GPU,HDDL"}});
+    //but you cannot add new devices on the fly, the next line will trigger the following exception: 
+    //[ ERROR ] [NOT_FOUND] You can only change device priorities but not add new devices with the Network's SetConfig(MultiDeviceConfigParams::KEY_MULTI_DEVICE_PRIORITIES.
+    //CPU device was not in the original device list!
+    exec.SetConfig({{"MULTI_DEVICE_PRIORITIES", "CPU,GPU,HDDL"}});
+//! [part1]
+return 0;
+}