bug#52958: [PATCH] doc: fix man page syntax errors

[Ondřej Fiala]

* doc/grep.in.1: Fix syntax errors.
Introduced by commit v3.6-5-g91ce9cd.
---
Commit 91ce9cdad introduced invalid roff into the manpage.
This should have been caught during code review as far as I can tell.

 doc/grep.in.1 | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/doc/grep.in.1 b/doc/grep.in.1
index ed53a8f..372b892 100644
--- a/doc/grep.in.1
+++ b/doc/grep.in.1
@@ -214,7 +214,9 @@ as basic regular expressions (BREs, see below).
 This is the default.
 .TP
 .BR \-P ", " \-\^\-perl\-regexp
-Interpret I<PATTERNS> as Perl-compatible regular expressions (PCREs).
+Interpret
+.I PATTERNS
+as Perl-compatible regular expressions (PCREs).
 This option is experimental when combined with the
 .B \-z
 .RB ( \-\^\-null\-data )
@@ -690,7 +692,9 @@ options match, a file is included unless the first such 
option is
 .BR \-r ", " \-\^\-recursive
 Read all files under each directory, recursively,
 following symbolic links only if they are on the command line.
-Note that if no file operand is given, B<grep> searches the working directory.
+Note that if no file operand is given,
+.B grep
+searches the working directory.
 This is equivalent to the
 .B "\-d recurse"
 option.
@@ -756,8 +760,11 @@ In other implementations, basic regular expressions are 
less powerful.
 The following description applies to extended regular expressions;
 differences for basic regular expressions are summarized afterwards.
 Perl-compatible regular expressions give additional functionality, and are
-documented in B<pcre2syntax>(3) and B<pcre2pattern>(3), but work only if
-PCRE support is enabled.
+documented in
+.BR pcre2syntax (3)
+and
+.BR pcre2pattern (3),
+but work only if PCRE support is enabled.
 .PP
 The fundamental building blocks are the regular expressions
 that match a single character.
-- 
2.34.1