use nicer typography in the default template (#780)

Squashed commit of the following:

commit eb310340ae542152ae5fd15b070e389a17b71913
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 17:24:19 2014 +0000

    Updated to use the same set of monospace typefaces as MDN too.

commit 5ff2591f8c3711e20f87eeb2e41347396d201414
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 17:15:28 2014 +0000

    Add font re-generation instructions to the README.

commit bb4502a308936a31684732104b09ae737e6fbaec
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 16:11:06 2014 +0000

    Added additional variations of the OpenSans typeface.

commit 125f2c91e767c7fa853ffa3222e7ed7d02f027b8
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 15:33:44 2014 +0000

    Moved the web fonts into a separate 'fonts' directory.

commit 968998c677a946e79910b96cff2cb4c29898eb48
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 15:24:46 2014 +0000

    Removed a negative margin hack we no longer seem to need.

commit 82f96d67cd3067ba6fd3deadee13e8853eb58491
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 15:13:15 2014 +0000

    Removed the 'Summary' heading, plus re-jigged the formatting so there isn't too much space before the content.

commit db9dfad5c2339ea6d36a400b59da0447d446920d
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 14:23:05 2014 +0000

    Fix for styling that was incorrectly being applied to each item in a list, rather than to the list itself.

commit 774271bd4e74ea429df7e5ae8fb9473097b81a1b
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 14:14:04 2014 +0000

    For consistency, ensure there is always a space after the colon used to delimit CSS rule pairs.

commit 88d59794b0442e594bedf6fb17a638923ac67c2a
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 14:07:31 2014 +0000

    Replace tabs with spaces to be consistent with the remainder of the stylesheet.

commit 37e5043403441a19cbe0cf2e2f4dec8ceba6cacb
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Wed Nov 5 14:02:34 2014 +0000

    Use the same color for headings that MDN does.

commit 8f925659efd7a6c9996bf2a8dcebb174f79dc8d8
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Fri Aug 22 09:46:41 2014 +0100

    Accidentally missed from previous check-in.

commit e98b060822b018c1403b98c92400052565d69e20
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Fri Aug 22 09:46:11 2014 +0100

    Updated the license to reflect the inclusion of the Open Sans typeface,
    plus included EOT and SVG versions of the font so that older version of
    IE and Android browser also get to see the page rendered correctly.

commit 7e1a581bca931603e738e5afc238e7f211c9d444
Author: Dominic Chambers <dominic.chambers@gmail.com>
Date:   Thu Aug 21 14:32:02 2014 +0100

    Rebased the template typography off of the Mozilla Developer Network
    site so generated API docs have a more contemporary and familiar style.