Add new functions, fix some white-space, and add our pledge(2) promises.

man/lowdown.3

@@ -43,9 +43,11 @@ library parses Markdown as defined in
 into HTML or roff
 .Pq Fl ms No or Fl man No macro sets .
 It consists of both a high-level interface consisting of
-.Xr lowdown_buf 3
-and
+.Xr lowdown_buf 3 ,
+.Xr lowdown_buf_diff 3 ,
 .Xr lowdown_file 3 ,
+and
+.Xr lowdown_file_diff 3 ;
 then a series of low-level interfaces directly to the parsers and
 renderers.
 .Pp
@@ -54,11 +56,11 @@ Most functions use the
 structure to manage features.
 .Bd -literal
 struct lowdown_opts {
-	lowdown_msg msg;
-	enum lowdown_type type;
-	void *arg;
-	unsigned int feat;
-	unsigned int oflags;
+  lowdown_msg msg;
+  enum lowdown_type type;
+  void *arg;
+  unsigned int feat;
+  unsigned int oflags;
 };
 .Ed
 .Pp
@@ -234,8 +236,8 @@ values if
 was provided as an input bit.
 .Bd -literal
 struct lowdown_meta {
-	char *key;
-	char *value;
+  char *key;
+  char *value;
 };
 .Ed
 .Pp
@@ -253,7 +255,7 @@ is given in
 .Vt "struct lowdown_opts" .
 .Bd -literal
 typedef	void (*lowdown_msg)
-	(enum lowdown_err, void *, const char *);
+  (enum lowdown_err, void *, const char *);
 .Ed
 .Pp
 It accepts the following arguments:
@@ -280,14 +282,31 @@ A footnote reference to an unknown footnote, and is thus being ignored.
 .It Dv LOWDOWN_ERR_DUPE_FOOTNOTE
 A duplicate footnote reference was encountered, and is thus being ignored.
 .El
+.Ss Pledge Promises
+The
+.Nm lowdown
+library is built to operate in security-sensitive environments, such as
+those using
+.Xr pledge 2
+on
+.Ox .
+The only promise required is
+.Va stdio
+for
+.Xr lowdown_file_diff 3
+and
+.Xr lowdown_file 3 :
+both require access to the stream for reading input.
 .Sh SEE ALSO
 .Xr lowdown 1 ,
 .Xr lowdown_buf 3 ,
+.Xr lowdown_buf_diff 3 ,
 .Xr lowdown_doc_free 3 ,
 .Xr lowdown_doc_new 3 ,
 .Xr lowdown_doc_parse 3 ,
 .Xr lowdown_errstr 3 ,
 .Xr lowdown_file 3 ,
+.Xr lowdown_file_diff 3 ,
 .Xr lowdown_html_free 3 ,
 .Xr lowdown_html_new 3 ,
 .Xr lowdown_html_rndr 3 ,