Update README.md

Added a fuller description

Author: beached

README.md

@@ -1,3 +1,27 @@
-# json_to_cpp
-Generate boilerplate C++ code, that uses parse_json library, from example json
+# JSON to C++
+This program will take either a json file or a URL to a web service and build C++ classes to work with that data.  By default it will create the serialization linkage for the JsonLink library that is part of https://github.com/beached/parse_json .
 
+# Requirements
+CMake >= 2.8.12 https://cmake.org/
+Boost >= 1.58 https://www.boost.com/
+Curl https://curl.haxx.se/
+
+Both Boost and Curl are often packaged within a Linux distribution and available for Windows/Mac
+
+# Building
+The build system uses cmake.  Often a build can be accomplished by creating a build folder in the project source folder and typing 
+```
+cmake ..
+cmake --build .
+```
+# Running
+To output the C++ code to the terminal one just needs to type json_to_cpp_bin --in_file jsonfile.json
+
+```
+Command line options
+Options:
+  --help                  print option descriptions
+  --in_file arg           json source file path or url
+  --out_file arg          output c++ file
+  --use_jsonlink arg (=1) Use JsonLink serializaion/deserialization
+```