Add doctype, html lang and meta charset.
Reindent html files for better readability.
Fix validation errors.

Also, add image dimensions and break long lines.
Reindent style.css.
Losslessly compress PNG files.

img/git-logo.png     | Bin 3668 -> 2758 bytes
img/msysgit-logo.png | Bin 8282 -> 6441 bytes

Total difference: -2751 bytes.
Use only the Bootstrap components that are needed.

Add bootstrap-info.md with all the needed info.

Also, the layout is responsive now.
Use the new ".io" domain GitHub pages is using.
Remove unneeded end tags.
Merge pull request #9 from XhmikosR/master

Various