Add \s for 'strong' text, i.e. bold rather than italics. I've missed

this a couple of times in Halibut markup recently (in particular, it's
handy to have a typographical distinction between 'this term is
emphasised because it's new' and 'this term is emphasised because I
want you to pay attention to it'), so here's an implementation,
basically parallel to \e.

One slight oddity is that strong text in headings will not be
distinguished in some output formats, since they already use bolded
text for their headings.

[originally from svn r9772]

1 files changed, 10 insertions, 5 deletions

diff --git a/doc/input.but b/doc/input.but
index 8cf4b8a..137f399 100644
--- a/doc/input.but
+++ b/doc/input.but
@@ -94,6 +94,10 @@ sentence in this paragraph was generated using the Halibut input
 \c Possibly the most obvious piece of formatting you might want
 \c to use in a document is \e{emphasis}.
 
+A second form of emphasis is supported, called \i\s{strong} text. You
+can use the \i\c{\\s} command for this type of emphasis. Typically, in
+output formats, \c{\\e} will give italics, and \c{\\s} will give bold.
+
 \S{input-code} \c{\\c} and \c{\\cw}: Displaying \i{computer code} inline
 
 Halibut was primarily designed to produce software manuals. It can
@@ -111,8 +115,9 @@ the text accurately and conveniently).
 
 Halibut provides \e{two} commands for this, which are subtly
 different. The names of those commands are \i\c{\\c} (\q{code}) and
-\i\c{\\cw} (\q{\i{weak code}}). You use them just like \c{\\e}, by
-following them with some text in braces. For example, this...
+\i\c{\\cw} (\q{\i{weak code}}). You use them just like \c{\\e} and
+\c{\\s}, by following them with some text in braces. For example,
+this...
 
 \c This sentence contains some \c{code} and some \cw{weak code}.
 
@@ -497,8 +502,8 @@ characters to escape.
 Since a backslash inside a code paragraph generates a literal
 backslash, this means you cannot use any other Halibut formatting
 commands inside a code paragraph. In particular, if you want to
-emphasise a particular word in the paragraph, you can't do that
-using \c{\\e} (\k{input-emph}) in the normal way.
+emphasise or strengthen a particular word in the paragraph, you can't
+do that using \c{\\e} or \c{\\s} (\k{input-emph}) in the normal way.
 
 Therefore, Halibut provides an alternative means of \i{emphasis in
 code paragraphs}. Each line beginning with \c{\\c} can optionally be
@@ -1125,7 +1130,7 @@ This will cause the word \q{grep} to appear in code style, as if the
 the word will also appear in code style in the actual index.
 
 If you want to simultaneously index and emphasise a word, there's
-another special case \i\c{\\i\\e}:
+another special case \i\c{\\i\\e} (and similarly \i\c{\\i\\s}):
 
 \c This is what we call a \i\e{paper jam}.