`HtmlConfig` was both guaranteed to exist within `BookConfig`
and `expect`ed in few places.
This simplifies the API a little by representing the fact that
`HtmlConfig` is currently mandatory for proper mdBook binary operation.
* This is a built-in function of iOS Safari that didn't work because the
page content was inside absolutely-positioned, scrollable divs.
* The fix is to stop using absolute positioning on `.page-wrapper` and
`.page`, so that the content uses static positioning and flows
naturally down the page.
* Consequently, `.sidebar` and `.nav-chapter` now have to use `position:
fixed` in order to be positioned relative to the viewport.
* This fix also enables Safari's built-in behavior of automatically
hiding the top and bottom toolbars when scrolling down the page.
Fixes a lot of browser incompatibilities in localStorage/cookie handling
Including but not limited to:
- loss of styling and functionality on chromium private mode
- loss of styling and functionality on safari and safari private mode
- awaiting verification if problems in mobile safari are solved.
List of system fonts (R, I, B means roman, italic and bold. Ubuntu probably comes with more fonts, but I couldn't find a list to confirm.):
```txt
Windows
----------
Consolas R RI B BI
Courier R
Courier New R RI B BI
Lucida Console R
Mac
----------
Andale Mono R
Courier R RI B BI
Courier New R RI B BI
Menlo R RI B BI
Monaco R
Ubuntu
----------
Ubuntu Mono R RI B BI
DejaVu Sans Mono R RI B BI
```
```css
font-family: Consolas, "Ubuntu Mono", Menlo, "DejaVu Sans Mono", monospace, monospace;
```
Consolas and Ubuntu are professionally designed fonts ([Lucas de Groot][1] and [Dalton Maag][2]), with true, calligraphic italic, so they go at the top of the stack.
Menlo is [based on DejaVu Sans Mono][3], the only difference being a few tweaked glyphs, so DejaVu serves as a fallback for it.
As for Courier New, other than being unreadably spindly, it's the default monospaced font in all browsers, so there's no need to include it in the stack.
The `monospace, monospace;` declaration is, by now, [a standard hack][4] that overrides some browsers' behaviour of defaulting the `monospace` elements to smaller font size. Without it, any relative font size you apply to them will be calculated from that reduced size (seems to be 13 px in all browsers).
[1]: https://en.wikipedia.org/wiki/Luc(as)_de_Groot
[2]: https://en.wikipedia.org/wiki/Dalton_Maag
[3]: http://www.leancrew.com/all-this/2009/10/the-compleat-menlovera-sans-comparison/
[4]: https://stackoverflow.com/questions/38781089/font-family-monospace-monospace
Hidden code blocks are no longer indented with
one additional space (required for doctests to compile in some cases)
Now the behavior is similar to the rustdoc's
Michal Budzynski
projektir
Michael Bryan
Mathieu David
Jimmy Do
pravic
Cldfire
aaaxx
Phil Ruffwind
Vincent Esche
Jesse Millikan
steveklabnik
CrazyMerlyn
Carol (Nichols || Goulding)
Pavel Ivashkov
