Merge pull request #2 from TimothyGu/newwork

Improvements for makeinfo-based documentation
web: Get rid of the dist folder and generate both dev/prod versions in the same folder htdocs

Makefile option to generate in development mode. Default is production.
Bower dependencies are in htdocs but updated by the Makefile when edited in development mode.
+ Remove useless files (unused images mainly)
web: Improve Makefile
web: remove local-npm.sh and update README
style: add "warning" style similar to .info but has a red border

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Add generate-doc.sh to generate makeinfo-based ffmpeg docs

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
CSS fix