Merge tag 'docs-4.9' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "This is the documentation update pull for the 4.9 merge window.

  The Sphinx transition is still creating a fair amount of work. Here we
  have a number of fixes and, importantly, a proper PDF output solution,
  thanks to Jani Nikula, Mauro Carvalho Chehab and Markus Heiser.

  I've started a couple of new books: a driver API book (based on the
  old device-drivers.tmpl) and a development tools book. Both are meant
  to show how we can integrate together our existing documentation into
  a more coherent and accessible whole. It involves moving some stuff
  around and formatting changes, but, I think, the results are worth it.
  The good news is that most of our existing Documentation/*.txt files
  are *almost* in RST format already; the amount of messing around
  required is minimal.

  And, of course, there's the usual set of updates, typo fixes, and
  more"

* tag 'docs-4.9' of git://git.lwn.net/linux: (120 commits)
  URL changed for Linux Foundation TAB
  dax : Fix documentation with respect to struct pages
  iio: Documentation: Correct the path used to create triggers.
  docs: Remove space-before-label guidance from CodingStyle
  docs-rst: add inter-document cross references
  Documentation/email-clients.txt: convert it to ReST markup
  Documentation/kernel-docs.txt: reorder based on timestamp
  Documentation/kernel-docs.txt: Add dates for online docs
  Documentation/kernel-docs.txt: get rid of broken docs
  Documentation/kernel-docs.txt: move in-kernel docs
  Documentation/kernel-docs.txt: remove more legacy references
  Documentation/kernel-docs.txt: add two published books
  Documentation/kernel-docs.txt: sort books per publication date
  Documentation/kernel-docs.txt: adjust LDD references
  Documentation/kernel-docs.txt: some improvements on the ReST output
  Documentation/kernel-docs.txt: Consistent indenting: 4 spaces
  Documentation/kernel-docs.txt: Add 4 paper/book references
  Documentation/kernel-docs.txt: Improve layouting of book list
  Documentation/kernel-docs.txt: Remove offline or outdated entries
  docs: Clean up bare :: lines
  ...

Documentation/sphinx-static/theme_overrides.css

@@ -42,6 +42,20 @@
     caption a.headerlink { opacity: 0; }
     caption a.headerlink:hover { opacity: 1; }
 
+    /* Menu selection and keystrokes */
+
+    span.menuselection {
+	color: blue;
+	font-family: "Courier New", Courier, monospace
+    }
+
+    code.kbd, code.kbd span {
+	color: white;
+	background-color: darkblue;
+	font-weight: bold;
+	font-family: "Courier New", Courier, monospace
+    }
+
     /* inline literal: drop the borderbox, padding and red color */
 
     code, .rst-content tt, .rst-content code {
@@ -55,5 +69,4 @@
     .rst-content tt.literal,.rst-content tt.literal,.rst-content code.literal {
         color: inherit;
     }
-
 }