misc: make json_append() non-static

This will be used to write json with a bstr in the next commit.

Co-authored-by: Kacper Michajłow <kasper93@gmail.com>

misc/json.c

@@ -289,7 +289,7 @@ static void add_indent(bstr *b, int indent)
         bstr_xappend(NULL, b, bstr0(" "));
 }
 
-static int json_append(bstr *b, const struct mpv_node *src, int indent)
+int json_append(bstr *b, const struct mpv_node *src, int indent)
 {
     switch (src->format) {
     case MPV_FORMAT_NONE:

misc/json.h

@@ -23,7 +23,10 @@
 
 #define MAX_JSON_DEPTH 50
 
+struct bstr;
+
 int json_parse(void *ta_parent, struct mpv_node *dst, char **src, int max_depth);
+int json_append(struct bstr *b, const struct mpv_node *src, int indent);
 void json_skip_whitespace(char **src);
 int json_write(char **s, struct mpv_node *src);
 int json_write_pretty(char **s, struct mpv_node *src);