updated readme

.gitignore

@@ -6,4 +6,4 @@
 *.zip
 nabto-libs
 build
-
+README.html

README.md

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+# Nabto CLI Demo
+
+This application demonstrates how to use the Nabto Client SDK to exercise certificate management, device discovery, RPC device invocation and tunnel management.
+
+## SDK installation
+
+To build the Nabto CLI Demo, first download the Nabto Client SDK bundle from https://www.nabto.com/downloads.html. Note: The demo uses the 4.1.0 version of the Nabto Client SDK; as of writing, only a pre-release version with linux64 libraries is available. This early version can be downloaded here: https://www.nabto.com/downloads/nabto-libs/4.1.0-rc1/nabto_libraries.zip
+
+After download, install the libraries and header files into the `lib` and `include` directories, so you have the following structure:
+
+```
+.
+├── CMakeLists.txt
+├── README.md
+├── include
+│   ├── cxxopts.hpp
+│   └── nabto_client_api.h
+├── lib
+│   ├── libnabto_client_api_static.a
+│   └── libnabto_static_external.a
+└── src
+    ├── nabto_cli.cpp
+    ├── tunnel_manager.cpp
+    └── tunnel_manager.hpp
+```
+
+Note that no resources are necessary to install, with the 4.1.0 release these come bundles in the SDK and are automatically installed by the demo app (through `nabtoInstallDefaultStaticResources` in the client API).
+
+## Building and running
+
+To build the app, a C++11 compiler and CMake must be available and the Nabto Client SDK installed as described above:
+
+```
+$ mkdir build
+$ cd build
+$ cmake ..
+-- The C compiler identification is AppleClang 8.1.0.8020042
+-- The CXX compiler identification is AppleClang 8.1.0.8020042
+-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc
+[...]
+$ make -j 9
+Scanning dependencies of target nabto-cli
+[ 66%] Building CXX object CMakeFiles/nabto-cli.dir/src/nabto_cli.cpp.o
+[ 66%] Building CXX object CMakeFiles/nabto-cli.dir/src/tunnel_manager.cpp.o
+[100%] Linking CXX executable nabto-cli
+[100%] Built target nabto-cli
+$ ./nabto-cli --help
+Nabto Command Line demo
+Usage:
+  ./nabto-cli [OPTION...]
+
+  -c, --create-cert             Create self signed certificate
+[...]
+```