Make builds easier

- In this PR I added a `sfnttol.jar` file to make the builds easier. 
- I added I paragraph in `README` to explain the build process.
- I also fixed in isse in makefile, the `web` directory wasn't created before the generation of wodd and eof files.
- I removed `WTT` variable in makefile as ttf fonts ain't used in the web directory actually.

Thank you  for this really nice font. Any remarks are welcome, I can change the way the PR is done if tou want. Don't hesitate.