doc: implement typesetting of keystrokes.

This commit relies on parallel improvements
in man2html, up through commit
ac186529b6b5f80906c3215a67c98505db7bb156
"Implement .M2HT request for HTML passthrough."

* genman.txr: Add CSS block targetting the kbd element,
providing 3D styling for keyboard input.

* txr.1: Define two new macros, .key and .keyn.
These are defined in three different ways: in man page
output, we put square brackets around keystrokes.
In typeset groff output, we put a square border around
them using a box macro cribbed from groff documentation.
In HTML, we use .M2HT to wrap a <kbd> tag around the
keystrokes. Documentatio is updated to use these macros
for all keystrokes. We no longer separate keystroke
sequence elements with commas.

1 files changed, 12 insertions, 0 deletions

diff --git a/genman.txr b/genman.txr
index 89aec557..07db7e04 100644
--- a/genman.txr
+++ b/genman.txr
@@ -194,6 +194,18 @@ dl.items dt {
   float: left;
   padding-right: 1ex;
 }
+kbd {
+  background-color: #eee;
+  border-radius: 3px;
+  border: 1px solid #b4b4b4;
+  box-shadow: 0 1px 1px rgba(0, 0, 0, .2), 0 2px 0 0 rgba(255, 255, 255, .7) inset;
+  color: #333;
+  display: inline-block;
+  font-weight: 700;
+  line-height: 1;
+  padding: 2px 4px;
+  white-space: nowrap;
+}
 </style>
 <script type="text/javascript">
 var xpanded = false;