Update build instructions

Merge branch 'master' of github.com:shtanton/gmi2html

Fix misinformation in README.md

No longer says that input can be provided using a filename

gmi2html Version 0.4.0

Makes the translation more semantic

Uses <p> elements and "display: block;" styles for layout instead of loads of <br/> tags.

gmi2html 0.2.1

New features:
- Improved error handling for invalid options
- Adds controls for `<video>` and `<audio>` elements
- `--help` and `--version` options

Removes the ability to use a file as input

Input can now only come from stdin

Adds various community files