basic: improve config file handling

- add `add-resource-path(string)` to add a new resource directory
- bind `load-file-from-path` on C-c C-f

qe.c

@@ -8105,6 +8105,13 @@ static int parse_command_line(int argc, char **argv)
     return _optind;
 }
 
+void do_add_resource_path(EditState *s, const char *path)
+{
+    QEmacsState *qs = s->qe_state;
+    pstrcat(qs->res_path, sizeof(qs->res_path), ":");
+    pstrcat(qs->res_path, sizeof(qs->res_path), path);
+}
+
 void set_user_option(const char *user)
 {
     QEmacsState *qs = &qe_state;

qe.h

@@ -1831,6 +1831,7 @@ int qe_load_file(EditState *s, const char *filename1,
 /* config file support */
 void do_load_config_file(EditState *e, const char *file);
 void do_load_qerc(EditState *e, const char *file);
+void do_add_resource_path(EditState *s, const char *path);
 
 /* popup / low level window handling */
 EditState *show_popup(EditBuffer *b);

qeconfig.h

@@ -428,7 +428,7 @@ static CmdDef basic_commands[] = {
           "ui{Fill column: }")
 
     /* other stuff */
-    CMD3( KEY_NONE, KEY_NONE,
+    CMD3( KEY_CTRLC(KEY_CTRL('f')), KEY_NONE,
           "load-file-from-path", do_load_file_from_path, ESsi, 0,
           "s{Load file from path: }|file|"
           "v")
@@ -438,6 +438,10 @@ static CmdDef basic_commands[] = {
     CMD2( KEY_NONE, KEY_NONE,
           "load-qerc", do_load_qerc, ESs,
           "s{path: }[file]|file|")
+    CMD2( KEY_NONE, KEY_NONE,
+          "add-resource-path", do_add_resource_path, ESs,
+          "s{resource path: }[file]|file|")
+
 
     CMD_DEF_END,
 };