Update README.md

If no output path is specified, the output is printed to stdout.

Added gitignore

Removed xcode files

Fixed bug where empty context file would result in app terminating.

Added each and zip functions (GRMustache)

Added functionality to convert markdown to html

Updated Readme

Updated extracting contents from file to have better error messages.

Updated replacement method when merging contexts. Now the newer context overrides the older

Fixed bug where using multiple files would not merge all contents together.

Added binary

Added Readme

Switched language to Swift